PD-L1 expression is increased in tumors providing them protection by reducing the activity of PD-1 expressing CD4 and CD8 T cells; monoclonal antibodies against PD-L1 have shown considerable results in melanoma, lung and renal cancer with clinical trials expanded in a variety of tumors including SCCHN [33]. The gene discussed is CD8A; the disease is head and neck squamous cell carcinoma.