Polymorphisms: GSTO1*A140D (C419A; rs4925), GSTO2*N142D (A424G; rs156697)Main findings:- no significant differences in GSTO1 and GSTO2 genotypes between HNSCC and controls;- significant association between wild-type GSTO1*A140 and nodal metastasis and advanced pathological stage;- no significant association between GSTO2*N142D variant and clinico-pathological features. Here, GSTO2 is linked to head and neck squamous cell carcinoma.