CD274 and head and neck squamous cell carcinoma: Pembrolizumab or Nivolumab, now approved for first line treatment of recurrent/metastatic HNSCC (43, 44). Improved response in PD-L1 expressing tumors (45–47), HPV not clearly associated with response (48, 49). Some patients may have sustained responsesMay be combined with chemotherapy (platinum & 5-FU) (50)May be combined with cetuximab based on antibody dependent cellular toxicity (51)