CD274 and melanoma: This understanding has led to the development and approval of monoclonal antibodies targeting the PD-1/PD-L1 pathway, which have transformed the therapeutic landscape of several difficult-to-treat malignancies, including melanoma, non-small cell lung cancer, renal cell carcinoma, and bladder and gastric cancers, where PD-L1 often serves as a predictive and prognostic biomarker [9].