CD274 and primitive neuroectodermal tumor: In the pancreatic neuroendocrine tumour model and the polyoma middle T oncoprotein (PyMT) breast cancer model (RT2-PNET), the concomitant administration of anti-VEGFR2 and PDL–1 antibodies promoted the development of specialised vessels known as High Endothelial Venules (HEVs), which support lymphocyte trafficking and enhance T-cell infiltration.