SMAD7 and hepatocellular carcinoma: Given the role of SMAD7 in the TGF-β signaling pathway and carcinogenesis of HCC, we performed a case-control study to comprehensively examine 3 loci (rs4939827, rs7240004, and rs7229639), which located at SMAD7 loci, for their associations with HCC risk and clinicopathologic development in a Han Chinese population, which accounts for 92% of the Chinese population [19, 20].