CircTMEM45A (has-circ-0066659) acts as a sponge for miR-665, regulating the expression of downstream insulin-like growth factor 2 (IGF2) to promote cell migration in vitro and the occurrence of HCC in vivo, and its expression correlates with tumor size, TNM staging, and vascular invasion. This evidence concerns the gene IGF2 and hepatocellular carcinoma.