GSTM3 and lip and oral cavity carcinoma: Majumder et al [20] reported the GSTM3 AA genotype could increase the risk of oral leukoplakia and cancer among smokers; in contrast, Jourenkova-Mironova et al [11] found the GSTM3 AA genotype was not associated with oropharyngeal cancer risk, and Buch et al [19] reported that no association between the GSTM3 alleles and oral cancer risk was observed.