to be a target for contraception. To date, however, there has been little translational research to determine the possible beneficial effects of EP2 antagonists or agonists in humans. The following drugs that act on EP2 but also other prostaglandin receptors are in clinical use: Iloprost activates EP2, EP3, and EP4 receptors to treat diseases involving pathological constriction of blood vessels such as pulmonary hypertension, Raynauds disease, and scleroderma. Presumably, it works by stimulating EP2, and EP4 receptors which have vasodilation actions. Misoprostol, an EP3 and EP4 receptor agonist, to prevent ulcers; to induce labor in pregnancy, medical abortion, and late miscarriage; and to prevent and treat postpartum bleeding. The following drugs are in development or proposed to be candidates for development as highly selective EP2 agonists for the indicated conditions: Butaprost for the treatment of pulmonary fibrosis and certain neurological diseases CP533,536 for the stimulation of bone formation Taprenepag isopropyl (PF-04217329) for the treatment of glaucoma and various neurological diseases (see above section on Nervous system) Genomic studies The single-nucleotide polymorphism (SNP) variant rs17197 in the 3' untranslated region of PTGER2 has been associated with an increased incidence of essential hypertension in a population of Japanese men. SNP variant rs1254598 in a Spanish population; SNP variant uS5 located in a STAT-binding consensus sequence of the regulatory region of PTGER2 with reduced transcription activity in a Japanese population; and two PTGER2 SNP variants (-616C>G and -166G>A) in a Korean population have been associated with an increased incidence of Aspirin-induced asthma. See also Prostanoid receptors Prostaglandin receptors Prostaglandin E2 receptor 1 (EP1) Prostaglandin E2 receptor 3 (EP3) Prostaglandin E2 receptor 4 (EP4) Eicosanoid receptor References Further reading External links G protein-coupled receptors