CD274 and brain neoplasm: As increased PD-L1 expression was observed after anti-angiogenic treatment, Allen et al. treated refractory pancreatic, breast and brain tumor mouse models with combined therapy using PD-1/PD-L1 pathway blockers and anti-angiogenic agents to increase the efficacy of anti-angiogenic therapy based on VEGF and VEGFR-2 inhibition.