Objectives:To assess the prognostic impact of the neoadjuvant rectal (NAR) score following neoadjuvant short-course radiotherapy and consolidation chemotherapy in locally advanced rectal cancer (LARC), as well as its value in guiding decisions for adjuvant chemotherapy.Methods:Between August 2015 and August 2018, patients were eligible from the STELLAR phase III trial (NCT02533271) who received short-course radiotherapy plus consolidation chemotherapy and for whom the NAR score could be calculated. Based on the NAR score, patients were categorized into low (＜8), intermediate (8-16), and high (＞16) groups. The Kaplan-Meier method, log rank tests, and multivariate Cox proportional hazard regression models were used to evaluate the impact of the NAR score on disease-free survival (DFS).Results:Out of the 232 patients, 24.1%, 48.7%, and 27.2% had low (56 cases), intermediate (113 cases), and high NAR scores (63 cases), respectively. The median follow-up period was 37 months, with 3-year DFS rates of 87.3%, 68.3%, and 53.4% ( P＜0.001) for the low, intermediate, and high NAR score groups. Multivariate analysis demonstrated that the NAR score (intermediate NAR score: HR, 3.10, 95% CI, 1.30-7.37, P=0.011; high NAR scores: HR=5.44, 95% CI, 2.26-13.09, P＜0.001), resection status ( HR, 3.00, 95% CI, 1.64-5.52, P＜0.001), and adjuvant chemotherapy ( HR, 3.25, 95% CI, 2.01-5.27, P＜0.001) were independent prognostic factors for DFS. In patients with R0 resection, the 3-year DFS rates were 97.8% and 78.0% for those with low and intermediate NAR scores who received adjuvant chemotherapy, significantly higher than the 43.2% and 50.6% for those who did not ( P＜0.001, P=0.002). There was no significant difference in the 3-year DFS rate (54.2% vs 53.3%, P=0.214) among high NAR score patients, regardless of adjuvant chemotherapy. Conclusions:The NAR score is a robust prognostic indicator in LARC following neoadjuvant short-course radiotherapy and consolidation chemotherapy, with potential implications for subsequent decisions regarding adjuvant chemotherapy. These findings warrant further validation in studies with larger sample sizes.

Objectives:To assess the prognostic impact of the neoadjuvant rectal (NAR) score following neoadjuvant short-course radiotherapy and consolidation chemotherapy in locally advanced rectal cancer (LARC), as well as its value in guiding decisions for adjuvant chemotherapy.Methods:Between August 2015 and August 2018, patients were eligible from the STELLAR phase III trial (NCT02533271) who received short-course radiotherapy plus consolidation chemotherapy and for whom the NAR score could be calculated. Based on the NAR score, patients were categorized into low (＜8), intermediate (8-16), and high (＞16) groups. The Kaplan-Meier method, log rank tests, and multivariate Cox proportional hazard regression models were used to evaluate the impact of the NAR score on disease-free survival (DFS).Results:Out of the 232 patients, 24.1%, 48.7%, and 27.2% had low (56 cases), intermediate (113 cases), and high NAR scores (63 cases), respectively. The median follow-up period was 37 months, with 3-year DFS rates of 87.3%, 68.3%, and 53.4% ( P＜0.001) for the low, intermediate, and high NAR score groups. Multivariate analysis demonstrated that the NAR score (intermediate NAR score: HR, 3.10, 95% CI, 1.30-7.37, P=0.011; high NAR scores: HR=5.44, 95% CI, 2.26-13.09, P＜0.001), resection status ( HR, 3.00, 95% CI, 1.64-5.52, P＜0.001), and adjuvant chemotherapy ( HR, 3.25, 95% CI, 2.01-5.27, P＜0.001) were independent prognostic factors for DFS. In patients with R0 resection, the 3-year DFS rates were 97.8% and 78.0% for those with low and intermediate NAR scores who received adjuvant chemotherapy, significantly higher than the 43.2% and 50.6% for those who did not ( P＜0.001, P=0.002). There was no significant difference in the 3-year DFS rate (54.2% vs 53.3%, P=0.214) among high NAR score patients, regardless of adjuvant chemotherapy. Conclusions:The NAR score is a robust prognostic indicator in LARC following neoadjuvant short-course radiotherapy and consolidation chemotherapy, with potential implications for subsequent decisions regarding adjuvant chemotherapy. These findings warrant further validation in studies with larger sample sizes.

The kidneys are one of the main excretory organs for drugs and when drugs are not excreted effectively, they can accumulate in the kidneys or in the interstitial tubules, leading to drug-induced kidney injury. The tubulointerstitium accounts for 80% of the volume of the kidney and is the primary site of response to various types of renal injury. This article focuses on drug-induced acute interstitial nephritis, highlighting its clinical symptoms, listing common induction drugs, analysing pathological features, and explaining its pathogenesis from the perspective of immune response, with the aim of providing a basic and clinical evidence for subsequent studies.

Objective:To investigate the clinical efficacy and prognostic influencing factors of radical surgery for duodenal gastrointestinal stromal tumor (GIST).Methods:The retrospective cohort study was conducted. The clinicopathological data of 741 duodenal GIST patients who under-went radical surgery in 17 medical centers, including 121 cases in Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine, 121 cases in Chinese PLA General Hospital, 116 cases in Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 77 cases in Fudan University Shanghai Cancer Center, 77 cases in West China Hospital, Sichuan University, 31 cases in Guangdong Provincial People′s Hospital, 24 cases in Fujian Cancer Hospital, 22 cases in Fujian Medical University Union Hospital, 25 cases in Shengjing Hospital of China Medical University, 19 cases in Xiangya Hospital, Central South University, 23 cases in Zhejiang Cancer Hospital, 17 cases in Liaoning Cancer Hospital＆Institute, 17 cases in the First Affiliated Hospital of Xiamen University, 15 cases in Sun Yat-sen University Cancer Center, 14 cases in the First Affiliated Hospital of Nanjing Medical University, 14 cases in Zhongshan Hospital Affiliated to Xiamen University and 8 cases in General Hospital of Chinese People′s Liberation Army Air Force, from January 2010 to April 2020 were collected. There were 346 males and 395 females, aged 55(range, 17?86)years. Observation indicators: (1) neoadjuvant treatment; (2) surgical and postoperative situations; (3) follow-up; (4) stratified analysis. Follow-up was conducted using outpatient examination or telephone interview. Patients were followed up once every 3?6 months during neoadjuvant therapy and once every 6?12 months after radical surgery to detect tumor recurrence and survival of patient up to April 2022. Measurement data with normal distribution were represented as Mean± SD. Measurement data with skewed distribution were represented as M(range), and comparison between groups was conducted using the Mann-Whitney U test. Count data were described as absolute numbers or percentages, and comparison between groups was conducted using chi-square test or Fisher exact probability. The Kaplan-Meier method was used to draw survival curves and calculate survival rates. Log-rank test was used for survival analysis. The COX regression model was used for univariate and multivariate analyses. Propensity score matching was done by the 1∶1 nearest neighbor matching method, and the matching tolerance was 0.02. Results:(1) Neoadjuvant therapy. Of the 741 patients, 34 cases received neoadjuvant therapy for 8(range, 3?44)months. Cases assessed as partial response, stable disease and progressive disease before the radical surgery of the 34 cases were 21, 9, 4, respectively. The tumor diameter of the 34 patients before the neoadjuvant therapy and before the radical surgery were 8.0(range, 3.0?26.0)cm and 5.3(range, 3.0?18.0)cm, with the regression rate as 31.9%(range, ?166.7% to 58.3%). (2) Surgical and postoperative situations. Of the 741 patients, 34 cases underwent radical surgery after receiving neoadjuvant therapy, and 707 cases underwent radical surgery directly. All the 741 patients underwent radical surgery successfully, in which 633, 102 and 6 cases received open surgery, laparoscopic surgery and endoscopic treatment, respectively. Of the 633 cases receiving open surgery and the 102 cases receiving laparoscopic surgery, cases with surgical resection range as pancreatoduodenectomy (PD) was 238, and cases with surgical resection range as duodenal limited resection, including duodenal wedge resection, distal gastrectomy, segmental duodenal resection, local resection of duodenal tumor or segmental duodenum combined with subtotal gastrectomy, was 497, 226, 55, 204, 12. Of the 741 patients, 131 cases had post-operative complications including 113 cases with grade Ⅰ?Ⅱ complications and 18 cases with ≥ grade Ⅲ complications of the Clavien-Dindo classification. The duration of postoperative hospital stay of the 741 patients was 13(range, 4?120)days. Of the 707 patients receiving direct radical surgery, 371 cases were evaluated as extremely low risk, low risk, medium risk of the modified National Institutes of Health (NIH) risk classification after surgery, and 336 cases were evaluated as high risk in which 205 cases receive postoperative adjuvant imatinib therapy with the treatment time as 24(range, 6?110)months. (3) Follow-up. All the 741 patients were followed up for 58(range, 7?150)months. During the follow-up, 110 patients had tumor recurrence and metastasis. The 1-, 3-, 5-year overall survival rates and 1-, 3-, 5-year disease-free survival rates of the 741 patients were 100.0%, 98.6%, 94.5% and 98.4%, 90.9%, 84.9%, respectively. The 1-, 3-, 5-year overall survival rates and 1-, 3-, 5-year disease-free survival rates of the 707 patients receiving direct radical surgery were 100.0%, 98.5%, 94.3% and 98.4%, 91.1%, 85.4%, respectively. (4) Stratified analysis. ① Analysis of prognostic factors in patients undergoing radical surgery directly. Results of univariate analysis showed that primary tumor location, tumor diameter, mitotic count, modified NIH risk classification and tumor gene information were related factors affecting the overall survival of 707 patients with primary duodenal GIST who underwent direct radical surgery ( hazard ratio=0.43, 0.18, 0.22, 0.06, 0.29, 95% confidence intervals as 0.20?0.93, 0.09?0.35, 0.10?0.50, 0.03?0.12, 0.09?0.95, P<0.05). The primary tumor location, tumor diameter, mitotic count, modified NIH risk classification were related factors affecting the disease-free survival of 707 patients with primary duodenal GIST who underwent direct radical surgery ( hazard ratio=0.65, 0.25, 0.25, 0.10, 95% confidence intervals as 0.41?1.03, 0.17?0.37, 0.15?0.42, 0.07?0.15, P<0.05). Results of multivariate analysis showed that primary tumor located at the horizontal segment of duodenum, mitotic count >5/50 high power field, tumor gene KIT exon 9 mutation were independent risk factors affecting the overall survival of 365 patients with primary duodenal GIST after removing 342 patients without tumor gene information who underwent direct radical surgery ( hazard ratio=2.85, 2.73, 3.13, 95% confidence intervals as 1.12?7.20, 1.07?6.94, 1.23?7.93, P<0.05). Tumor diameter >5 cm and mitotic count >5/50 high power field were independent risk factors affecting the disease-free survival of 707 patients with primary duodenal GIST who underwent direct radical surgery ( hazard ratio=3.19, 2.98, 95% confidence intervals as 2.05?4.97, 1.99?4.45, P<0.05). ② Effect of postoperative adjuvant therapy on prognosis of high-risk patients of modified NIH risk classification. Of the 336 patients evaluated as high risk of the modified NIH risk classification, the 5-year overall survival rate and 5-year disease-free survival rate were 94.6% and 77.3% in the 205 cases with postoperative adjuvant therapy, versus 83.2% and 64.4% in the 131 cases without postoperative adjuvant therapy, showing significant differences between them ( χ2=8.39, 4.44, P<0.05). Of the 205 patients evaluated as high risk of the modified NIH risk classification who received postoperative adjuvant therapy, there were 106 cases receiving postoperative adjuvant therapy <36 months, with the 5-year overall survival rate and 5-year disease-free survival rate were 87.1% and 58.7%, and there were 99 cases receiving post-operative adjuvant therapy ≥36 months, with the 5-year overall survival rate and 5-year disease-free survival rate were 100.0% and 91.5%. There were significant differences in the 5-year overall survival rate and 5-year disease-free survival rate between the 106 patients and the 99 patients ( χ2=13.92, 29.61, P<0.05). ③ Comparison of clinical efficacy of patients with different surgical methods. Before propensity score matching, cases with primary tumor located at bulb, descending, horizontal, ascending segment of duodenum, cases with tumor diameter ≤5 cm and >5 cm were 95, 307, 147, 34, 331, 252, in the 583 patients receiving open surgery with complete clinical data, versus 15, 46, 17, 5, 67, 16 in the 83 patients receiving laparoscopic surgery with complete clinical data, showing no significant difference in the primary tumor location ( χ2=0.94, P>0.05), and a significant difference in the tumor diameter ( χ2=17.33, P<0.05) between them. After propensity score matching, the above indicator were 16, 39, 20, 8, 67, 16 in the 83 patients receiving open surgery, versus 15, 46, 17, 5, 67, 16 in the 83 patients receiving laparoscopic surgery, showing no significant difference between them ( χ2=1.54, 0.00, P>0.05). Cases with postoperative complications, cases with grade Ⅰ?Ⅱ complica-tions and ≥grade Ⅲ complications of the Clavien-Dindo classification, duration of postoperative hospital stay, the 5-year overall survival rate and 5-year disease-free survival rate were 17, 12, 5, 11(range, 5?120)days, 92.0%, 100.0% in the 83 patients receiving open surgery, versus 9, 7, 2, 11(range, 5?41)days, 91.6%, 97.3% in the 83 patients receiving laparoscopic surgery, showing no signi-ficant difference in postoperative complications, duration of postoperative hospital stay, the 5-year overall survival rate and 5-year disease-free survival rate ( χ2=2.91, Z=3 365.50, χ2=3.02, 1.49, P>0.05) between them. There was no significant difference in complications of the Clavien-Dindo classification between them ( P>0.05). ④ Comparison of clinical efficacy of patients with primary tumor located at the descending segment of duodenum who underwent surgery with different surgical resection scopes. Before propensity score matching, cases with tumor diameter ≤5 cm and >5 cm, cases with tumor located at opposite side of mesangium and mesangium were 71, 85, 28, 128 in the 156 patients with primary tumor located at the descending segment of duodenum who underwent PD with complete clinical data, versus 92, 41, 120, 13 in the 133 patients with primary tumor located at the descending segment of duodenum who underwent duodenal limited resection with complete clinical data, showing significant differences between them ( χ2=16.34, 150.10, P<0.05). After propensity score matching, the above indicator were 28, 13, 16, 25 in the 41 patients with primary tumor located at the descending segment of duodenum who underwent PD with complete clinical data, versus 28, 13, 16, 25 in the 41 patients with primary tumor located at the descending segment of duodenum who underwent duodenal limited resection with complete clinical data, showing no significant difference between them ( χ2=0.00, 0.00, P>0.05). Cases with postopera-tive complications, cases with grade Ⅰ?Ⅱ complications and ≥grade Ⅲ compli-cations of the Clavien-Dindo classification, duration of postoperative hospital stay, the 5-year overall survival rate and 5-year disease-free survival rate were 13, 11, 2, 15(range, 9?62)days, 94.2%, 64.3% in the 41 patients with primary tumor located at the descending segment of duodenum who underwent PD with complete clinical data, versus 9, 8, 0, 15(range, 7?40)days, 100.0%, 78.8% in the 41 patients with primary tumor located at the descending segment of duodenum who underwent duodenal limited resection with complete clinical data, showing no significant difference in post-operative complica-tions, the 5-year overall survival rate and 5-year disease-free survival rate ( χ2=0.99, 0.34, 1.86, P>0.05) between them. There was no significant difference in complications of the Clavien-Dindo classification ( P>0.05) and there was a significant difference in duration of postopera-tive hospital stay ( Z=614.50, P<0.05) between them. Conclusions:The clinical efficacy of radical surgery for duodenal GIST are ideal. Primary tumor located at the horizontal segment of duodenum, mitotic count >5/50 high power field, tumor gene KIT exon 9 mutation are independent risk factors affec-ting the overall survival of patients undergoing direct radical surgery and tumor diameter >5 cm and mitotic count >5/50 high power field are independent risk factors affecting the disease-free survival of patients. There is no significant difference in the short-term efficacy and long-term prognosis between patients undergoing open surgery and laparoscopic surgery. For patients with primary tumor located at the descending segment of duodenum, the duration of postoperative hospital stay is longer in patients undergoing PD compared with patients undergoing duodenal limited resection. For patients evaluated as high risk of the modified NIH risk classification, posto-perative adjuvant therapy and treatment time ≥36 months are conducive to improving the prognosis of patients.

Objective:To identify the risk factors of non-sentinel lymph node (nSLN) metastasis in breast cancer patients with 1~2 positive axillary sentinel lymph node (SLN) and construct an accurate prediction model.Methods:Retrospective chart review was performed in 917 breast cancer patients who underwent surgery treatment between 2002 and 2017 and pathologically confirmed 1-2 positive SLNs. According to the date of surgery, patients were divided into training group (497 cases) and validation group (420 cases). A nomogram was built to predict nSLN metastasis and the accuracy of the model was validated.Results:Among the 917 patients, 251 (27.4%) had nSLN metastasis. Univariate analysis showed tumor grade, lymphovascular invasion (LVI), extra-capsular extension (ECE), the number of positive and negative SLN and macro-metastasis of SLN were associated with nSLN metastasis (all P<0.05). Multivariate Logistic regression analysis showed the numbers of positive SLN, negative SLN and macro-metastasis of SLN were independent predictors of nSLN metastasis (all P<0.05). A nomogram was constructed based on the 6 factors. The area under the receiver operating characteristic curve was 0.718 for the training group and 0.742 for the validation group. Conclusion:We have developed a nomogram that uses 6 risk factors commonly available to accurately estimate the likelihood of nSLN metastasis for individual patient, which might be helpful for radiation oncologists to make a decision on regional nodal irradiation.

Objective:To identify the risk factors of non-sentinel lymph node (nSLN) metastasis in breast cancer patients with 1~2 positive axillary sentinel lymph node (SLN) and construct an accurate prediction model.Methods:Retrospective chart review was performed in 917 breast cancer patients who underwent surgery treatment between 2002 and 2017 and pathologically confirmed 1-2 positive SLNs. According to the date of surgery, patients were divided into training group (497 cases) and validation group (420 cases). A nomogram was built to predict nSLN metastasis and the accuracy of the model was validated.Results:Among the 917 patients, 251 (27.4%) had nSLN metastasis. Univariate analysis showed tumor grade, lymphovascular invasion (LVI), extra-capsular extension (ECE), the number of positive and negative SLN and macro-metastasis of SLN were associated with nSLN metastasis (all P<0.05). Multivariate Logistic regression analysis showed the numbers of positive SLN, negative SLN and macro-metastasis of SLN were independent predictors of nSLN metastasis (all P<0.05). A nomogram was constructed based on the 6 factors. The area under the receiver operating characteristic curve was 0.718 for the training group and 0.742 for the validation group. Conclusion:We have developed a nomogram that uses 6 risk factors commonly available to accurately estimate the likelihood of nSLN metastasis for individual patient, which might be helpful for radiation oncologists to make a decision on regional nodal irradiation.

Objective To evaluate the risk factors of non-sentinel lymph node (NSLN) metastasis in breast cancer patients with 1-2 positive sentinel lymph nodes and to establish a new Nomogram prediction model.Methods Clinicopathological data of breast cancer patients who were diagnosed with 1-2 positive lymph nodes and underwent axillary lymph node dissection (ALND) without neoadjuvant chemotherapy from January 2008 to December 2014 were retrospectively analyzed.Measurement data between two groups were analyzed by chi-square test.Multivariate analysis was performed by logistic regression model.The prediction accuracy of the Nomogram model was evaluated using the area under the receiver operating characteristic curve (AUC) and calibration curves.Results A total of 270 patients were recruited in this study.Among them,87(32.2％) patients had NSLN metastases.The median age was 46 years old (21-80 years),the median number of SLNs was 4 (1-10) and the median number of axillary lymph nodes was 20(10-41).Univariate analysis demonstrated that the pathological grade,the size of SLN metastasis,the number of negative and positive SLNs were the risk factors of NSLN metastasis (P=0.001-0.045).Multivariate analysis showed that pathological grade,the number of negative and positive SLNs were independent risk factors of NSLN metastasis (P=0.000-0.041).The AUC value of Nomogram prediction model for NSLN metastasis was 0.70.The false negative rate of Nomogram was 10.5％ when the cut-off point of predictive probability was ≤ 15％.Conclusions The Nomogram is a useful prediction model for evaluating NSLN metastasis.ALND or axillary radiotherapy can be avoided for patients with a low probability of NSLN metastasis.

Objective: The clinical features and prognosis of diffuse large B-cell lymphoma (DLBCL) were analyzed to optimize the treatment. Methods: We retrospectively collected the clinical data of patients with advanced-stage DLBCL from January 2006 to December 2012 in National Cancer Center/Cancer Hospital. The demographic characteristics, clinical stage, histological diagnosis, treatment and prognostic characteristics of these patients were analyzed. Results: A total of 370 patients with median age of 55 years old were recruited in the study. The male-to-female ratio was 1.3∶1. Among the 361 patients who underwent therapy, 280 cases received chemotherapy alone, 65 cases received chemoradiotherapy, and 16 cases received chemotherapy combined with autologous hematopoietic stem cell transplantation (AHSCT). The median follow-up period was 89 months, the 5-year overall survival (OS) rate of the entire cohort was 42.9%. The 5-year OS rate of chemotherapy alone, chemoradiotherapy and chemotherapy combined with AHSCT were 36.8%, 58.5%, 87.5%, respectively. The 5-year OS rate were significantly different between chemoradiotherapy and chemotherapy alone (P=0.001), and between chemotherapy combined with AHSCT and chemoradiotherapy (P=0.040). Univariate analysis showed that the age, Eastern Cooperative Oncology Group performance status (ECOG PS) score, Ann Arbor stage, B symptom, bulky disease, number of extranodal sites, Ki-67 index, lactate dehydrogenase (LDH), β2-microglobulin (β2-MG), international prognostic index (IPI), therapeutic manner and chemotherapy combined with rituximab were significantly associated with the prognosis of advanced DLBCL patients (all P<0.05). Multivariate analysis demonstrated that the age >60 years, Ann Arbor stage IV, with B symptom, with bulky disease, ECOG PS≥1, Ki-67 index > 90%, CD5 expression, up-regulation of serum LDH and β2-MG, and chemotherapy without rituximab were related with the poor prognosis of patients with advanced-stage DLBCL (all P<0.05). Conclusions Chemotherapy combined with rituximab can improve the outcome of patients with advanced-stage DLBCL. The age, stage, B symptom, bulky disease, ECOG PS score, Ki-67 index, CD5 expression, LDH, β2-MG and chemotherapy combined with rituximab are associated with the prognosis of these patients.

Background and objective Cisplatin is the ifrst-line drug for the chemotherapy of non-small cell lung cancer (NSCLC), but the acquired chemoresistance restricted the effect of its treatment. hTe aim of this study is to validate the miRNAs related to the Cisplatin resistance in lung cancer and elucidate the molecular mechanisms. Methods We performed miRNA microarray and RT-PCR to obtain the aberrant differential expressed miRNAs between A549 and its paired Cisplatin-resistant cell line A549/DDP cells, and then we investigated the biological functions of miR-192, which is the aberrant differen-tial expressed miRNA. Atfer transfection of the miR-192 into A549 cells, we measured the half inhibition concentration (IC50), cell apoptosis of the trasfectant cells, and then we used biological sotfwares and dual-luciferase report assay to explore the target gene of the miR-192, which was further validated by RT-PCR and Western blot. Result MiR-192 was highly over-expressed in A549/DDP cells , whose quantity was 37.59±0.35 fold higher than that in A549 cells. Overexpression of miR-192 in A549 cells signiifcantly conferred resistance to Cisplatin and inhibited apoptosis. By contrast, down-expression of miR-192 in A549/DDP cells remarkably restrained the Cisplatin resistance and induced apoptosis. MiR-192 binded to Bim 3’-UTR and negatively regulated Bim expression at the post-transcriptional level in lung adenocarcinoma cells. Conclusion Our data suggested that miR-192 induced Cisplatin-resistance and inhibited cell apoptosis in lung cancer via negative targeting Bim expression.

Background and objective hTe methods for introducing point mutations into target genes are impor-tant for dissecting the relationship of gene structure and function. Up to date, there are numbers of protocols available for the purpose. However, many of them are suited for introducing single site mutation into the target gene. For introducing multiple-site mutations simultaneously into the target genes, it is required to further improve the related methods. Methods In this report, we describe an improvement on the type IIs restriction enzyme-dependent site-directed mutagenesis method and the improved protocol is highly effcient for multiple-site mutagenesis. In our method, a pair of mutagenic primers are synthesized for each desired site and each mutagenic primer contains a selected type IIs restriction site. hTe DNA fragments between two neighboring sites are ampliifed with PCR. All ampliifed fragments are then digested by the selected Type IIs restriction enzyme. hTe expected mutant is eventually generated by ligation of these digested DNA fragments. Results hTe improved protocol is very easy and can be achieved in just one day. As a proof of principle, we have introduced multiple-site, i.e., 3-site or 4-site mu-tations into the fusion gene of nm23 and EGFP (enhanced green lfuorecence protein). hTe mutagenic frequencies are almost reached 100%. Conclusion Our protocol provides a useful tool for gene function research.