CD274 and neoplasm: Patient tumor biopsies were assayed for PDL1 expression using immunohistochemistry (IHC) and expressed as a combined positive score (CPS, positive tumor cells and immune cells divided by the total number of cells). PD-L1 expression and high (TMB) may predict better responses to ICIs, but patients without these biomarkers may still respond to immunotherapy. Additional caveats include a lack of standardization, tumor heterogeneity and other factors influencing the TME.