In this regard, pre-clinical data has demonstrated the ability of Ad-p53 to reverse resistance to anti-PD-1/anti-PD-L1 therapy in cancer models (13, 14) and these findings led to the initiation of a Phase 2 clinical trial of combined Ad-p53 and anti-PD-1 therapy in recurrent HNSCC and other cancers (https://clinicaltrials.gov/ct2/show/NCT03544723). Here, TP53 is linked to head and neck squamous cell carcinoma.