In this regard, it is important to consider that the level of PD-L1 expression on cancer cells as a predictive biomarker for the efficacy of PD-1/PD-Ls blockade has been proved by IHC in many trials, across different types of solid tumors, in particular melanoma and Non-Small Cell Lung Cancer (NSCLC) (52, 53). The gene discussed is CD274; the disease is melanoma.