In terms of MAOA and MAOB, after adjusting for covariates, compared with the healthy control group (MAOA rs6323 T allele and MAOB rs6324 A allele), we found that subjects with MAOA rs6323 (G-allele) and MAOB rs6324 (G-allele) had a significantly increased risk of oral and pharyngeal cancers (AOR = 30.32; 95% CI, 13.07–70.35) and risk of OPMD (AOR = 53.21; 95% CI, 10.91–259.62). The gene discussed is MAOB; the disease is pharynx cancer.