The mechanistically hypothesized function of CMTM6 in post-translational PD-L1 stabilization and the empirically observed comparability of the staining patterns of both markers in HNSCC emphasize the need for a more precise assessment via co-localization in the membranous tumor compartment, for example, using double immunofluorescence, as recently proposed [51]. This evidence concerns the gene CD274 and head and neck squamous cell carcinoma.