TP53 and head and neck squamous cell carcinoma: While HPV-positive HNSCC cells usually encode a wild-type (wt) p53, which is then inactivated and degraded by the HPV oncoproteins E6, E7 and others, rendering the HPV-positive HNSCC functionally p53-deficient [76,77,78], the HPV-negative HNSCC can be divided into two groups, based on their p53 status: p53 wt and p53 mutated (mut).