If active EPAC-1/RAP1 confers a neuroprotective phenotype on microglia, then EPAC-1–specific agonists, such as the cAMP analog 8-(4-chloro-phenylthio)-2′-O-methyladenosine-3′,5′-cyclic monophosphate, may have therapeutic value in PD (47). Here, RAPGEF3 is linked to Parkinson disease.