BAX and hepatocellular carcinoma: HECTs are second only to human RING E3 ligases in number, and their HECT structural domains consist of an N-terminal lobe, a C-terminal lobe, and a flexible chain (26).Knockdown of WWP2 (HECT-type) significantly elevated the expression levels of apoptosis-related markers in HCC) cell lines, including caspase-7, caspase-8, and Bax, suggesting that inhibition of WWP2 may be a therapeutic tool to negatively regulate HCC overproliferation and escape apoptosis (40).