Technically, the PD-L1 protein expression is determined using the 22C3 pharmDx (Agilent Technologies, Santa Clara, California, USA) by Combined Positive Score (CPS), which is the number of PD-L1 staining cells (tumor cells, lymphocytes, macrophages) divided by the total number of viable tumor cells, multiplied by 100. The gene discussed is CD274; the disease is neoplasm.