CD274 and head and neck carcinoma: With the introduction of immune checkpoint therapies such as PD1 and PD-L1 inhibitors, the prognosis of cancer patients with various malignancies such as melanoma [29], non-small cell lung cancer [30], renal carcinoma [31], urothelial carcinoma [32], head and neck carcinoma [33] and Hodgkin lymphoma has significantly improved [34].