In a rFSH GnRH antagonist protocol, Papanikolaou et al[10] showed that women with ≥13 follicles ≥11 mm on the day of hCG were at increased risk of developing moderate to severe OHSS, while women with ≥18 follicles ≥11 mm were at increased risk of developing severe OHSS. The gene discussed is GNRH1; the disease is ovarian hyperstimulation syndrome.