Subsequently, silencing and overexpression of P21 and Cyclin A2 showed that silencing P21 or overexpression of Cyclin A2 alleviated PD2-mediated senescence of HCC cells, indicating that P21/Cyclin A2 signaling pathway is a key pathway for PD2-mediated senescence of HCC cells. This evidence concerns the gene CCNA2 and hepatocellular carcinoma.