Endometriotic implants are dependent on estrogen for their maintenance and growth (Dizerega et al. 1980; Gurates and Bulun 2003), and reduction of estradiol production, via either surgical (oophorectomy) or hormonal (GnRH agonist analogues) intervention, causes atrophy of endometriosis lesions and is effective in treating pain symptoms. The gene discussed is GNRH1; the disease is endometriosis.