CDKN2A and head and neck cancer: MCM7 and CDKN2A (p16) were proposed as biomarkers for HPV-positive head and neck cancer (Strati et al, 2006), while CDKN2A (p16) alone was suggested as a marker in HPV-infected oropharyngeal cancers with favourable prognosis (Weinberger et al, 2006).