Tang et al. [46] selected 21 case–control studies for a meta-analysis in 2010 and investigated the potential effect of CYP2E1 rs2031920 and rs3813867 in the risk of head and neck cancer; they found that the homozygote genotype of CYP2E1 rs2031920/rs3813867 may be linked to the risk of head and neck cancer, especially in Asian populations. The gene discussed is CYP2E1; the disease is head and neck cancer.