WNK2 and hepatocellular carcinoma: Mitogen-activated protein kinase (MAPK) is a serine/threonine kinase that plays an important role in regulating cell activity and signal transduction, including cell proliferation, differentiation, survival, death, and transformation, and is closely related to the occurrence and transfer of HCC, especially in HCC caused by HBV infection, because HBV can encode a regulatory protein (HBx).