CD274 and neoplasm: In diagnostic surgical pathology, immunohistochemistry is used to assess the PD-L1 status by applying the tumor proportion score (TPS; percentage of PD-L1 positive tumors cells) and the combined positivity score [CPS; number of PD-L1 staining cells (tumor cells, lymphocytes, macrophages) divided by the total number of viable tumor cells, multiplied by 100].