Association of clinical and tumor characteristics, XPC c.2815A>C, XPD c.934G>A, XPD c.2251A>C, XPF c.2505T>C and ERCC1 c.354C>T single nucleotide polymorphisms genotypes with survival of head and neck squamous cell carcinoma patients treated with chemoradiotherapy in univariate Cox analysis. Here, ERCC4 is linked to head and neck squamous cell carcinoma.