GIPR and Cushing syndrome due to macronodular adrenal hyperplasia: The ectopic expression of GIPR in the human adrenal gland causes significant hypercortisolemia after ingestion of a meal and leads to food-dependent Cushing’s syndrome (FD-CS), demonstrating that activation of human GIPR is capable of robustly activating adrenal glucocorticoid secretion [21]–[25].