RAPGEF3 and Hyperglycemia: The expression of both isoforms, Epac1 and Epac2 are elevated after exogenous treatment of exendin-4 (Ex-4), a dipeptidyl peptidase IV (DPP-IV)-resistant GLP-1 analog, which promotes differentiation of fetal pancreatic tissue, pancreatic progenitors, and intestinal stem cells into insulin-producing cells and ameliorates hyperglycemia [135,136].