Liu and colleagues have demonstrated that a decrease in 5hmC amounts is related to the progression of HCC via down‐regulation of the TET1 protein.18 In contrast, Gao and colleagues62 have evaluated nine HCC samples and demonstrated a decrease in TET1 and TET2 but not TET3 mRNA expression with concomitant down‐regulation of 5hmC. The gene discussed is TET1; the disease is hepatocellular carcinoma.