CDKN2A and head and neck squamous cell carcinoma: Though tobacco and alcohol consumption are thought to be the most common risk factors for developing HNSCC, viral infections have also been indicated to play an important role in malignancy.30,31 The role of HPV in oral and oropharyngeal carcinoma was first proposed by Syrjänen et al. in 1983 and subsequently favored by others.31–34 Several different studies have indicated that overexpression of the p16INK4A protein by IHC can serve as a surrogate biomarker of HPV-induced carcinomas.34–36 However, the results vary for p16 expression in OED.