CDKN2A and head and neck squamous cell carcinoma: In over 1362 HNSCC from the United States, Brazil, and Europe, D’souza et al. found that p16-positive cases had a lower risk of death compared to p16-negative cases among non-OP HNSSCs in univariate analysis (HR = 0.74, 95% CI = 0.57–0.96), but it was not confirmed after adjusting for other risk factors (aHR = 0.83, 95% CI = 0.60–1.14) (101).