AR and neoplasm: Adenosine was demonstrated to promote VEGF production in rat myocardial myoblasts [97] and in macrophages from C57BL/6 mice [98] It has been demonstrated that AR stimulation could increase VEGF production five-fold in tumor-associated CD45+ immune cells, an effect that is not observed in CD45+ cells from A2BAR KO mice [96] The A2BAR induces production of VEGF [23,96,99] and interleukin (IL)-8 in human melanoma cells [46], which are essential for tumor angiogenesis.