To elucidate the effects of the ERα/PRLR signaling interaction on bromocriptine resistance in prolactinomas, the present study aimed to establish a bromocriptine-resistant prolactinoma MMQ cell line (MMQ/BRO), which was employed alongside primary cultured human pituitary adenoma (HPA) cells. The gene discussed is PRLR; the disease is pituitary gland adenoma.