When there are enough embryos after fresh embryo transfer cycles, when a freeze-all strategy is utilized after a gonadotrophin-releasing hormone (GnRH) agonist trigger in GnRH antagonist protocols for patients at risk of ovarian hyperstimulation syndrome (OHSS), when late-follicular progesterone rise occurs, and when there is embryo-endometrial asynchrony, FET is accomplished (5). The gene discussed is GNRH1; the disease is ovarian hyperstimulation syndrome.