CD274 and neoplasm: Meta-analysis evaluating the discordance rate of PD-L1+ showed 51.2% of immune cells within primary sites stained positive vs. 37.1% of metastatic foci, and 30.1% of tumor cells in primary sites vs. 14.6% in distant sites and on further analysis of studies with matched primary and metastatic biopsies 13.6% of patients had discordance when PD-L1 status was assessed on tumor cells, 39.5% when assessed on immune cells, and 47.6% when assessed on both tumor and immune cells [10].