EP4, or Prostaglandin E receptor 4, is a human gene encoded by PTGER4. It may also be known as: Prostaglandin E2 receptor EP4 subtype; PGE2 receptor EP4 subtype; Prostanoid EP4 receptor; PGE receptor EP4 subtypeR; prostaglandin E receptor 4 (subtype EP4). The encoded protein has an amino acid length of 488 and a mass of 53.1 kDa. Other isoforms may exist. EP4 is a member of the G-protein coupled receptor 1 family. Homologs of this gene exist in other organisms, including: Mouse, Rat, Zebrafish, Frog, Chicken.