Circ-0003998 can act as a ceRNA of miRNA-143-3p to impair the expression inhibition of FOS-like antigen 2 (FOSL2) (EMT-related stimulator); meanwhile, circ-0003998 can also combine with poly(rC) binding protein 1 (PCBP1) to increase the expression of CD44v6 (EMT-related genes), then promote the EMT process of HCC (74). This evidence concerns the gene FOSL2 and hepatocellular carcinoma.