MMP2 and hepatocellular carcinoma: In an immortalized hepatocyte line, the MET protein, caveolins, and S100 family members in HCC-derived exosomes triggered PI3K/AKT and MAPK signaling pathways and increased the secretion of matrix metalloproteinase-2 (MMP-2) and MMP-9, thereby facilitating the invasion activity of cancer cells [43].