Furthermore, the expression of exosomal miR-122 released by hepatocellular carcinoma (HCC) Huh7 cells is restrained by insulin-like growth factor 1 (IGF-1) secreted from the recipient HCC HepG2 cells, which can also reduce the expression of miR-122 in Huh7 cells, thereby ensuring HepG2 cell growth (Basu and Bhattacharyya, 2014). Here, IGF1 is linked to hepatocellular carcinoma.