MET and hepatocellular carcinoma: In addition, exosomes derived from highly metastatic cells (LM3) with a high abundance of circPTGR1 might enhance the metastatic potential of lower metastatic cells (97L and HepG2) by inhibiting miR-449a-MET interaction, resulting in destruction on tumor microenvironment and thereby promoting HCC development (Wang G. et al., 2019).