We test the hypothesis that the surveillance of DNA methylation in five tumour-suppressor genes (RASSF1α, p16INK4a, TIMP3, PCQAP/MED15) will allow us to diagnose HNSCC patients from a normal healthy control group as well as to discriminate between Human Papillomavirus (HPV)-positive and HPV-negative patients. This evidence concerns the gene CDKN2A and head and neck squamous cell carcinoma.