Prolactin (PRL), also known as lactotropin and mammotropin, is a protein that (helps or) has role in enabling mammals to produce milk.
It is (a player or) or has influence in over 300 separate processes in various vertebrates, including humans. Prolactin (comes from or) is secreted from the pituitary gland. It comes as a response to eating, mating, estrogen treatment, ovulation and nursing.