MAPK8 and hepatocellular carcinoma: In line with our observation that ectopic GADD45G expression induces cell senescence and activates the p38 MAPK and JNK pathways, GADD45 proteins have been shown to induce cell cycle arrest at G2/M phase in HepG2 hepatoma cells, wherein the p38 MAPK and JNK act critically [40].