The MT-1 A-G-T haplotypes (MT1A rs8052394 A allele, MT1B rs964372 G allele, and MT1B rs8052334 T allele) are related to an increased susceptibility of hepatocellular carcinoma (HCC), especially in those who smoke, presenting a notable combined effect of cigarette smoking and MT-1 haplotypes on HCC development (Wong et al., 2013). Here, MT1A is linked to hepatocellular carcinoma.