CDKN2A and head and neck squamous cell carcinoma: Since a novel prognostic biomarker is urgently needed in HPV-negative HNSCC specifically, a prospective study to further investigate the role of CDKN2A hypermethylation in HPV-negative HNSCC patients as a potential prognostic biomarker would be imperative to advance the management of HPV-negative HNSCC patients.