– cGMP-dependent 3′,5′-cyclic phosphodiesterase, also known as cyclic GMP-stimulated phosphodiesterase and PDE2A, is a peripheral membrane protein that belongs to the cyclic nucleotide phosphodiesterase family and PDE2 subfamily. Phosphodiesterases (PDEs) comprise a family of enzymes that regulate the levels of cyclic nucleotides, key second messengers that mediate a diverse array of functions. Phosphodiesterases (PDEs) modulate signaling by cyclic nucleotides in diverse processes such as cardiac contractility, platelet aggregation, lipolysis, glycogenolysis, and smooth muscle contraction. PDE2A is an evolutionarily conserved cGMP-stimulated cAMP and cGMP PDE. PDE2A contains two GAF domains. PDE2A is expressed in brain and to a lesser extent in heart, placenta, lung, skeletal muscle, kidney and pancreas. PDE2A is a cyclic nucleotide phosphodiesterase with a dual-specificity for the second messengers cAMP and cGMP, which are key regulators of many important physiological processes. PDE2A is involved in the regulation of blood pressure and fluid homeostasis by the atrial natriuretic peptide (ANP), making PDE2-type enzymes important targets for drug discovery.