CCNF and neoplasm: Studies have shown that CCNF not only regulates the transformation of tumor cells from G1 to S phase by affecting the expression of E2F family genes (8) but also promotes the degradation of E2F7/8 protein via ubiquitination to induce the transition of tumor cells from the G2 phase to the M phase, and both of these processes occur independent of the interaction between cyclin-dependent kinase (CDK) and anaphase-promoting complex/cyclosome (APC/C) (9).