Prostaglandin E₂ receptor 4 is a prostaglandin receptor for prostaglandin E2 encoded by the PTGER4 gene in humans. It is one of four identified EP receptors, the others being EP₁, EP₂, and EP₃, all of which bind with and mediate cellular responses to PGE₂ and also, but generally with lesser affinity and responsiveness, certain other prostanoids. From Wikipedia
