The effects of cAMP are transduced by two intracellular receptors, PKA/cAPK and EPAC/cAMP-GEF. Both are ubiquitously expressed and an increase in cAMP levels activates both. Determining the individual roles and contributions of EPAC and PKA is important for understanding cAMP signaling. No EPAC-specific antagonists or agonists have been reported, making the development of EPAC-specific pharmacological probes a challenge. Identifying regulators of EPAC could lead to new therapeutic strategies for conditions such as diabetes, heart disease, and cancer. Is the molecule effective to this assay?