DNA double-strand break repair (DSBR) pathways are important repair pathways in human. DSBR pathways repair damaged DNA, maintain the integrity of the genetic information and therefore suppress cancer. More and more researches have indicated important roles of DSBR pathway genes in the development and treatment of ovarian cancer.

The binding complex of chemokine receptor CXCR4 and its specific ligand CXCL12 triggers the downstream signaling pathway to form biological axis of CXCR4/CXCL12. The axis plays an important role in homing, repopulation of hematopoietic stem cells, as well as maintenance of normal hematopoiesis and homeostasis of hematopoietic microenvironment. Meanwhile, CXCR4/CXCL12 axis is also closely related with relapsed leukemia, since it may promote survival, proliferation, metastasis and drug resistance in leukemic cells.The expression level of CXCR4 could be treated as an important marker for predicting prognosis in patients wizh leukemia, therefore, the combination of CXCR4 inhibitors with routine chemotherapy may represent a powerful approach for the treatment of leukemia.

Anthracycline-based chemotherapeutic agents were extensively applied to the treatment of breast cancer. The relation of its response to TOP2A gene was proved by a number of clinical studies demonstrating that patients with both HER2 gene amplification and TOP2A gene aberration have a favored outcome,but a consensus was not yet achieved.

During radiotherapy, ionizing radiation can damage some structures of the heart, including pericardium, myocardium, cardiac valve, conducting system, and coronary artery. Radiation-induced cardiac injury can manifest as abnormalities in many aspects including myocardium enzymes, perfusion imaging, electrocardiogram, strain rate imaging.

Secondary lymphoid tissue chemokine (CCL21) is a double-edged sword, which exerts antitumor, anti-infection immune response by binding to the receptor CCR7 on the surface of the multiple immune cells. However, a variety of tumor cells also express the receptor CCR7, the combination of CCL21 with CCR7promotes the invasion and metastasis of tumor cells, leading to the facilitation of tumor development. Therefore,exploring the mechanism(s) of tumor invasion and metastasis might be helpful for use of CCL21 as tumor gene therapy through blocking of CCL21's promotion of tumor invasion and metastasis.

Periostin, a extracellular matrix protein structurally similar to fasciclin proteins, is expressed specifically in various tumor tissues and correlates with tumor progression and prognosis. Periostin prevents the apoptosis of tumor cells, promotes tumor growth and can induce angiogenic signaling cascades through αvβ3-FAK and Flk-1/KDR. It also contributes to epithelial-mesenchymal-transformation promoting tumor invasion and metastasis. Periostin maybe a potential therapeutic target of cancer treatment.

Let-7 is one of the most widely studied in miRNAs at present. let-7 can inhibit cell proliferation, promote cell differentiation and apoptosis, etc. Reduced expression of let-7 in different human tumor tissues or cells is accompanied by the changes of its target genes expression, which suggests that let-7 is closely linked to cancer.

Multidrug resistance gene MDR1 C3435T polymorphism influences tumor incidence and treatment outcome. Carcinogenic substances are easier to accumulate in tissue for T allele patients, so TT genotype patients are more likely to develop into breast neoplasms, stomach neoplasms and colorectal neoplasms.Besides, the chemotherapy treatment outcome for patients with both C3435T TT genotype and wild-type KRAS is the best. However, due to ethnic, regional and sample differences, the relationship between C3435T polymorphism and stomach neoplasms 、colorectal neoplasms is still unclear.

WNT5A is associated with embryonic development and the development, invasion, metastasis and chemoresistance of tumor cells. The WNT5A signal in different tumors is specifically mediated by a number of factors, including receptors, downstream targets, inhibitors and external influences from tumor microenvironment and extracellular matrix. Eventhough it is still under debate whether WNT5A functions as a tumor suppressor or a promoter, WNT5A signal transduction pathway is closely associated with various tumor behaviors.

The combination of chemotherapy, radiotherapy and targeted therapies are considered to be major treatments for metastatic pancreatic cancer. At present, the target therapy-related medications include mainly antagonist of epidermal growth factor receptor, monoclonal antibody of vascular endothelial growth factor and so on. Erlotinib combined with gemcitabine has been demonstrated to prolong the survival of patients with pancreatic cancer.