– The A1, A2A, A2B, and A3 adenosine receptors (ARs) are ubiquitous G protein-coupled receptors. The four AR subtypes have been implicated in several areas of therapeutic interest such as stroke and other ischemic conditions, as well as inflammation, neurodegenerative diseases, diabetes, and sleep regulation. A3 AR antagonists are of interest as therapeutic agents in glaucoma agents and inflammation. CAY10498 is a potent and selective A3 AR antagonist exhibiting a Ki of 37 nM with 60 and 200-fold selectivity over A1 and A2A adenosine receptors, respectively. CAY10498 is also a structural analog of reversine, a dedifferentiation agent of embryonic progenitor cells. However, no dedifferentiation effects or any connection between A3 AR antagonism and dedifferentiation have been demonstrated.