TP53 and head and neck squamous cell carcinoma: TP53 mutations are present in the vast majority of SCLCs (up to 98%) [10, 38, 40], whereas HPV‐driven cancers, including previously reported cervical adeno‐ and squamous cell carcinomas [37], head and neck squamous cell carcinomas [36], and the UCSCCs from this study, displayed lower TP53 mutation frequencies (3–22%; Fig. 4A).