PRLR (Prolactin Receptor): PRLR is a receptor that binds to the hormone prolactin, which plays a role in milk production, reproductive functions, and immune regulation. When prolactin binds to PRLR, it triggers signaling pathways that control cell growth, development, and differentiation. Abnormal PRLR signaling has been connected to breast and other cancers, highlighting its importance in cell proliferation and its potential as a target for therapy.