CDKN1B and hepatocellular carcinoma: This interaction induces phosphorylation of ubiquitin-like with PHD and ring finger domains 2 (UHRF2) at serine 643, inhibiting UHRF2 ubiquitination.209 CDK2 is a cyclin-dependent kinase, and UHRF2 is a nuclear protein involved in cell cycle regulation, both playing critical roles in the development of HCC.210,211 Furthermore, HBx can upregulate arrestin beta 1 (ARRB1) protein, which drives HBV-related HCC by regulating autophagy and the CDKN1B-CDK2-CCNE1-E2F1 axis.212