We previously found that PRMT9 promotes metastasis and is highly expressed in high metastatic HCC cells [12], MHCC97H is a high metastatic potential cell, and HepG2 and Huh7 are low metastatic cells, so we chose to do gain-of-function experiments in HepG2 and Huh7 cells and loss-of-function experiments in MHCC97H. This evidence concerns the gene PRMT9 and hepatocellular carcinoma.