MKI67 and hepatocellular carcinoma: PP2A is a serine/threonine phosphatase that can act as a promoter or inhibitor of tumors and is involved in a variety of intracellular signaling pathways, including PI3K/AKT, MYC, WNT/β-catenin, and EGF/EFGR signaling (24, 33–35), where PP2A can directly dephosphorylate AKT, MYC and β-catenin, thereby regulating signaling pathway activity (36–43).I In hepatocellular carcinoma cells, a decrease in PPP2R3A resulted in G1/G2 arrest, a decrease in Ki67, and an increase in P53 and P21 (44).