Objective To investigate the expression and significance of cyclin dependent kinase inhibitor 3(CDKN3)in human papillomavirus type 16(HPV16)-positive cervical cancer.Methods CDKN3 expression in pan-cancer was retrieved and downloaded from the Gene Expression Profiling Interactive Analysis(GEPIA)platform,and the expression levels of CDKN3 between normal cervical tissues(13 samples)and cervical cancer tissues(306 samples)were compared.Subsequently,GSE39001 data of HPV16-positive cervical cancer was sourced and downloaded from the Gene Expression Omnibus(GEO)database,and the expression levels of CDKN3 mRNA in HPV16-positive cervical cancer tissues(43 samples)and normal cervical tissues(12 samples)were compared.Immunohistochemical method was used to detect the expression of CDKN3 in 12 ca-ses of HPV16-positive cervical cancer,12 cases of HPV16-positive cervical precancerous lesions,10 cases of HPV16-positive chronic cervicitis and 7 cases of HPV-negative normal cervical samples collected from the Af-filiated Hospital of Guizhou Medical University.SiHa(HPV16-positive),HeLa(HPV18-positive)and HCC94(HPV-negative)cervical cancer cell lines were selected,and their CDKN3 expression were detected by West-ern blot.Results The GEPIA platform analysis showed that CDKN3 was highly expressed in pan-cancer,and the expression level of CDKN3 in cervical cancer tissue was significantly higher than that in normal cervical tissue(P<0.05).The GEO dataset reflected a significantly increased CDKN3 mRNA expression level in HPV16-positive cervical cancer compared to normal cervical tissue(P<0.001).Immunohistochemical verifi-cation showed that the positive expression rates of CDKN3 in HPV16-positive cervical cancer,HPV16-positive cervical precancerous lesion,HPV16-positive chronic cervicitis and HPV-negative normal cervical tissues were 91.7%,58.3%,0 and 0,respectively.Western blot analysis of cervical cancer cells showed that the expression level of CDKN3 in SiHa(HPV16-positive)cells was significantly higher than that in HeLa(HPV18-positive)and HCC94(HPV-negative)cells(P<0.05).Conclusion CDKN3 is a new oncogene of HPV16-positive cer-vical cancer,which may be used as a marker of cervical precancerous lesions and cervical cancer screening,and may provide a theoretical basis for subsequent mechanism research and targeted therapy.