Zhang et al have shown that TET1 was the direct target of miR‐29a through the 3′‐UTR of mRNA.50 Further evidence has revealed that the miR‐29 family modulates active DNA demethylation through direct targeting of TET1 in multiple solid cancers.51, 52 Lin et al have investigated the potential function of the negative feedback of miR‐29‐TET1 in HCC tumorigenesis and its potential mechanisms.53 Furthermore, miR‐29a overexpression up‐regulates DNA methylation of the suppressor of cytokine signalling 1 (OSCS1) promoter; this process has been implicated in HCC metastasis in vitro and in vivo. The gene discussed is TET1; the disease is hepatocellular carcinoma.