It is important that the impairment of villous trophoblast syncytialization characterized by the decreased trophoblastic expression of GCM1 and syncytin-1, a fusogenic protein regulated by GCM1, has been observed in preeclampsia (47, 48), an obstetrical syndrome originating from impaired early placentation (49, 50). The gene discussed is GCM1; the disease is preeclampsia.