This idea was extended in in vitro studies which revealed that treatment of pancreatic β‐cell islets with physiological concentrations of dopamine antagonized GIP‐stimulated increases in cytosolic cAMP and subsequent insulin secretion.26 Taken together these data suggest that gut‐derived dopamine could act as an anti‐incretin to prevent hypoglycemia in healthy individuals, and that this inhibitory circuit is in some way dysregulated in diabetes. Here, INS is linked to diabetes mellitus.