To verify the form of SIAH2 mediated ubiquitination of HBx, HCC cells were co‐transfected with HIS‐SIAH2 and WT or mutant HA‐Ub vectors, HBx was co‐precipitated with anti‐FLAG or HBx antibodies, and the levels of exogenous and endogenous HBx ubiquitination were determined by western blotting with an HA antibody. This evidence concerns the gene SIAH2 and hepatocellular carcinoma.