Up to now, α-PD-1/PD-L1 treatments have exhibited potent antitumor activities in various cancers, such as melanoma, non-small cell lung cancer (NSCLC), gastric cancer, liver cancer, urothelial cancer, lymphoma, and all MSI-high cancers [2, 9,10,11,12,13,14,15,16,17,18,19].

Do all cancer cells express PD-L1?

PD-L1 is expressed on the cell surface in most human cancers and correlates with poor prognosis in many solid tumors, most likely by providing an immune escape mechanism through downregulation of tumor-specific T-cell responses [122].

Do cancer cells express PD-L1?

In addition, PD-L1 is also expressed on a wide range of tumor cells, including lung cancer, breast cancer and melanoma. PD-1 and PD-L1 are important members of the immunoglobulin super-family and participate in immune regulation.