In ovarian cancer cell lines EFO-21 and EFO-27 that had been shown to express high affinity GnRH-R and to secrete GnRH, treatment with an antiserum to GnRH in neutralizing concentrations significantly increased proliferation by 21%, while treatment with native GnRH even at very low concentrations (1 pM) had no effect or an anti-proliferative effect. The gene discussed is GNRH1; the disease is ovarian cancer.