MAPK3 and hepatocellular carcinoma: First, p62 binds to mitogen-activated protein kinase kinase kinase 3 (MEKK3) through an N-terminal oligomerization domain (PB1), which leads to mTORC1 activation and c-Myc expression, thus promoting cancer cell proliferation in prostate cancer stromal fibroblasts and HCC [5, 14].