ISG15 and hepatocellular carcinoma: A previous study reported that ISG15 could stimulate HCC cell growth.[21] We consistently observed that deletion of ISG15 (Figure S2A, Supporting Information) resulted in reduced viability and migration (Figures 3A, and S2B, Supporting Information); whereas ISG15 overexpression enhanced migration in Hep3B and HepG2 cells (Figure S2C, Supporting Information), suggesting that ISG15 promotes the proliferation of HCC cells.