 Through interactions with an array of cellular partners, EPAC1 has been shown to form discrete signalsomes at plasma membrane, nuclear-envelope, and cytoskeleton, where EPAC1 regulates numerous cellular functions.Studies based on genetically engineered mouse models of EPAC1 have provided valuable insights into understanding the in vivo functions of EPAC1 under both physiological and pathophysiological conditions.Overall, mice deficient of EPAC1 or both EPAC1 and EPAC2 appear relatively normal without major phenotypic defects.