PD-L1 is currently the most widely validated, used and accepted biomarker, expressed by pathological tissue tumor proportional score (TPS) or tumor cell (TC), defined as the percentage of tumor cells with partial or complete membranous PD-L1 staining relative to all tumor cells in the sample is used to guide patients’ selection of anti-PD-1 or anti-PD-L1 inhibitors, with patients with high TPS or TC scores more likely to benefit from ICIs treatment [22]. Here, PDCD1 is linked to neoplasm.