The known full A3AR agonist, 2-chloro-N6-(3-iodobenzyl)adenosine-5′-N-methyluronamide (Cl-IB-MECA, also called CF-102 or Namodenoson, 2, Figure 1), has been extensively studied on tumor cell proliferation and this compound has been reported to inhibit cancer cell proliferation in in vitro and in vivo tumor models [15,16]. Here, ADORA3 is linked to cancer.