The study by Beck et al reveals a dynamic pool of phosphorylation events downstream of the ADP receptors P2Y₁ and P2Y₁₂ that are counteracted by the prostaglandin I₂ (PGI₂) analog iloprost, which signals via protein kinase A (PKA). Phosphatases are shown to play a central role in regulating these phosphorylation events; however, biochemical links to the receptors remain ambiguous. AC, adenylate cyclase; ATP, adenosine triphosphate; cAMP, cyclic adenosine monophosphate; PGI₂R, prostaglandin I₂ receptor. Professional illustration by Patrick Lane, ScEYEnce Studios.