Mechanistically, researchers have revealed that circRNA-0003998 promotes expression of CD44v6 and EMT-related genes through direct binding to poly (rC) binding protein 1 (PCBP1) and acts as a competing endogenous RNA (ceRNA) of miR-143-3p, stimulating expression of FOS-like antigen 2 (FOSL2) to support EMT in HCC. Here, FOSL2 is linked to hepatocellular carcinoma.