Prolactin is a hormone synthesised and secreted by lactotrope cells in the adenohypophysis (anterior pituitary gland). Prolactin has many effects, the most significant of which is to stimulate the mammary glands to produce milk (lactation). Increased serum prolactin during pregnancy causes enlargement of the mammary glands of the breasts and increases the production of milk. Recently, prolactin has demonstrated broader roles in breast cancer development, regulation of reproductive function, and immunoregulation. Prolactin was expressed in E. coli and purifed by conventional chromatography, after refolding of the isolated inclusion bodies in a renaturation buffer. Alternative Names: Mammotropin protein, Prolactin precursor., Lactogenic hormone protein, PRL protein, Prolactin protein, OTTHUMP00000017727 protein, Luteotropic hormone protein