EGFR and head and neck squamous cell carcinoma: Importantly, our data, including a wide variety of patients and settings, underline that a one size fits all approach is not feasible: EGFR allowed clear delineation between CSCC or HNSCC and the surrounding tissue, except in areas where normal squamous epithelium, glands, and adnexa were in proximity to the tumor, and αvβ6 showed intense tumor expression with minimal staining in the basal layer of the dermis, but also exhibited an “on/off” phenomenon [24,25,26,27,28,29,30].