PDCD1 and head and neck squamous cell carcinoma: Given the potential clinical relevance of these results, we next studied whether there was an association between the percentage of Ecad+, Vim+, CD80+, CD155+, Ecad−Vim+, Ecad−CD80+ and Ecad−CD155+ cancer cells and the risk of disease progression after anti-PD-1/PD-L1 therapy in cSCC and HNSCC patients or of relapse during adjuvant anti-PD-1 therapy in melanoma patients (Fig. 7o).