PCNA and liver cancer: RSV also downgraded cell cycle-regulated proteins such as retinoblastoma (Rb), cyclin-dependent kinase 2 (CDK2), CDK4, cyclin E, cyclin D1, and proliferating cell nuclear antigen (PCNA) [41], which inhibits the Akt pathways, causing the death of bladder cancer cell, liver cancer cell, and rats aortic vascular smooth muscle cell.