Inhibition of platelet activation by cyclic nucleotide generation. PGI₂ and NO activation of cyclic nucleotide generation provide generalized inhibition of platelet activation. AC, adenylate cyclase; ATP, adenosine triphosphate; cAMP, cyclic adenosine monophosphate; cGMP, cyclic guanosine monophosphate; Gs, guanine nucleotide-binding protein stimulatory; GTP, guanosine triphosphate; PKA, protein kinase A; PKG, protein kinase G; sGC, soluble guanlyate cyclase. Professional illustration by Patrick Lane, ScEYEnce Studios.