Cyclins are positive regulatory subunits of the cyclin-dependent kinases (CDKs), and thereby play an essential role in the control of the cell cycle, notably via their destruction during cell division. Its tissue specificity suggest that it may be required during early meiotic prophase I. Interacts with CDK2 kinase. Testis specific. In testis, it is expressed in developing germ cells, but not in Leydig cells. Weakly or not expressed in other tissues. The N-terminal destruction box (D-box) probably acts as a recognition signal for degradation via the ubiquitin-proteasome pathway. Ubiquitinated (Probable). Ubiquitination leads to its degradation during anaphase entry, after degradation of CCNB1. Belongs to the cyclin family. Cyclin AB subfamily.