CD274 and neoplasm: The latter condition is established through the recruitment of suppressive immune cells, the polarization of immune and stromal cells towards a pro-tumoral phenotype, the production of immunosuppressive cytokines, or the tumour or stromal cell expression of inhibitory immune checkpoint molecules (e.g., CTLA-4 and PD-L1) that can negatively affect the proper functioning of tumour-infiltrating lymphocytes.