TREX1 and head and neck squamous cell carcinoma: Except for a strong increase in STING expression in FaDu FANCA ko cells, which, however, was not accompanied by an increase in its downstream activity and an IFN-1 response, the FANCA ko rather led to a downregulation of the general protein levels of the cGAS/STING pathway, as well as of TREX1 and PD-L1 in both HNSCC cell lines.