GSTP1 and head and neck squamous cell carcinoma: Previous analyses of this prospective study conducted by our group demonstrated that GSTP1 c.313A>G17, XPD c.934G>A15, EXO1 c.1762G>A15,16, FAS c.-671A>G18 SNVs of single pathways influenced response rate (RR) and/or PFS, RFS, EFS, and OS of HNSCC patients treated with CDDP chemoradiation.