PDCD1 and neoplasm: Overall survival rates remain rather poor despite multi-modal treatment approaches composed of surgical removal of the primary tumor and cervical lymph nodes, (neo)adjuvant radio(chemo) therapy (RCT), and targeted therapy, including epidermal growth factor receptor (EGFR)- and programmed cell death protein 1 (PD1) and programmed death ligand (PD-L1)-specific biologicals.