Anti-müllerian hormone: hormone or growth factor?

Anti-Müllerian hormone (AMH) is a dimeric glycoprotein member of the TGF-beta family. It is synthesized by immature Sertoli cells, and, to a lesser degree, by adult Sertoli and granulosa cells. AMH is responsible for the regression of Müllerian ducts in the male fetus; it also has deleterious effects on the female fetal reproductive tract, destroying Müllerian primordia and germ cells, and masculinizing the fetal ovary on the rare occasions female fetuses become exposed to its effects. All other suggested actions for AMH--retardation of oocyte meiosis, inhibition of EGF receptor autophosphorylation, anti-cancer activity--have been reported with crude hormone preparations, and have not been confirmed using pure AMH. Its relatively limited sphere of action--the fetal genital tract--and the fact that it is secreted into the general circulation and can act at long range, imply that AMH is more like a hormone than a growth factor, but the complex interaction between hormones and growth factors make a formal distinction impossible.