In addition, ectopic Siah-1 expression lowered HBx levels, whereas Siah-1 knockdown elevated HBx levels in human hepatoma cells, regardless of the presence of p53 and H2O2 (Figure 5a,b), confirming the p53-independent action of Siah-1 on HBx [46]. The gene discussed is TP53; the disease is hepatocellular carcinoma.