CD274 and metastatic malignant neoplasm: Clinical experience of ICIs in solid tumors has shown that IO therapy brings long-term disease control in at least 10–20% of the patients with metastatic cancers (more favorable in malignant melanoma, renal cell cancer, and non-small cell lung cancer with high PD-L1 expression, and MSI-high tumors) even after discontinuation of chemotherapy.