PCNA and prostate cancer: CCNB2 is a member of the cyclin family that regulates the cell cycle in eukaryotes by activating CDC2 kinase, and inhibition of CCNB2 induces cell cycle arrest.[19] CCNB2 has been reported to be overexpressed in a variety of human cancers, such as endometrial cancer, skin cancer, prostate cancer, and gastric cancer.