COMT and pharynx cancer: Subjects with MAOA rs1137070 (T-allele) and COMT rs4633 (C/C genotype) had a significantly increased risk of oral and pharyngeal cancers (AOR = 3.57; 95% CI, 1.86–6.82) and risk of OPMD (AOR = 5.31; 95% CI, 1.76–16.00).