In the present case-controlstudy, we aimed to examine the relationship between the CYP1A1 Ile/Val, exon 4 mEH(139 Arg → His), and GSTM1 nullgenetic polymorphism and the risk of oral and pharyngeal cancers, investigatingalso the association with smoking, drinking, and the gene-gene interactions. Here, GSTM1 is linked to pharynx cancer.