CD274 and neoplasm: The role of circulating EVs in the functionality of macrophages was investigated analysing their ability i) to modulate the expression of PD-L1 in macrophages, ii) to release selected cytokines involved in the establishment of the immunosuppressive phenotype and in the development of the neoangiogenesis and iii) to modulate the migration of the two subtypes M1 and M2 towards the tumor.