CD274 and neoplasm: Fragments of the tumor tissue were used to (i) evaluate exhaustion markers expressed by tumor-infiltrating lymphocytes (TILs) (Figure 2C) and (ii) prepare formalin-fixed, paraffin-embedded tumor tissues for immunohistochemistry using antibodies for Ki67, PD-L1, and CD3 and stain with hematoxylin-eosin.