The HPV-positive oropharyngeal squamous cell carcinoma cell line, UPCI-SCC90 [40], and the HNSCC cell line, UPCI-SCC154 [41], were reported to harbour reduced levels of BRCA2 and other DNA repair proteins, in comparison to HPV-negative cell lines [40, 41]. This evidence concerns the gene XRCC6P5 and oropharynx squamous cell carcinoma.