Loss of p53-mediated repression of APOBEC3B transcription, resulting either from TP53 mutation (observed at high frequency in HPV-negative HNSCC and ESCC) or from HPV E6/E7 activity in HPV-positive HNSCC (Vieira et al, 2014; Periyasamy et al, 2017) is also likely an important driver of APOBEC3B expression seen in many of the SCC samples we analysed. Here, TP53 is linked to head and neck squamous cell carcinoma.