Huang et al. [34] reported that proliferation of SMMC-7721 cells, a HCC cell line, could be greatly promoted by exogenous DLK1 while colony formation, cell growth, and tumorigenicity of Huh-7, Hep3B, and HepG2 cells can be greatly inhibited by the suppression of endogenetic DLK1 via RNA interference. This evidence concerns the gene DLK1 and hepatocellular carcinoma.