MTNR1B and hepatocellular carcinoma: While adjusted for age and alcohol use, we found that a specific haplotype of MTNR1B (GCGT) was significantly associated with increased susceptibility to HCC (AOR, 2.132; 95% CI, 1.106–4.111; p = 0.024), further suggesting a genetic predisposition of MTNR1B to liver cancer.