Since these effects are virtually unexplored in HNSCC, we investigated the impact of IR and CDDP with concomitant impairment of the DDR by inhibition of the ATR-Chk1 axis or knockout of the FA repair pathway on cGAS/STING/IFN-1 signaling in two HNSCC cell lines. This evidence concerns the gene ATR and head and neck squamous cell carcinoma.