The use of a 3–6 months of GnRH agonist treatment prior to IVF/ICSI in patients with endometriosis has been previously suggested to improve clinical pregnancy rates, but whether this effect was to be related to an endometrial or an ovarian benefit remained unexplained, according to the results of the Cochrane review by Sallam et al. (2006) [3]. Here, GNRH1 is linked to endometriosis.