PRLR and prolactin-producing pituitary gland adenoma: The metoclopramide test has been developed in the 70’s as a strong stimulator of PRL secretion (31) and is used to distinguish hPRL due to pituitary adenoma from other causes of hPRL (32), with a cut off of 300% being admitted as a limit of PRL stimulation beyond which hPRL is unlikely due to PRLoma (14).