Described by his peers as a world-leading medicinal chemist, who has produced a remarkable number of selective agonists and antagonists, as well as radioligands and photoaffinity labels for both P1 (adenosine) and P2Y (ATP, UTP and UDP) G protein-coupled receptor (GPCR) subtypes, new drugs discovered by his team are currently being developed not only for therapeutic applications, for example cancer and autoimmune inflammatory diseases, such as rheumatoid arthritis and psoriasis, but also for important unmet medical needs, such as chronic neuropathic pain, which affects a large fraction of the population. In addition, over three dozen chemical probes introduced by the Jacobson lab are available commercially as research tools and are used widely for the study of purine receptors, other GPCRs and ion channels.