ESR1 and Infertility: When samples from the control infertile group (group 1B) were compared with samples from the OE infertile group (group 2B), higher levels of the NR5A1 (P < 0.0001), STAR (P < 0.0001), CYP19A (P < 0.01), ESR1 (P < 0.05) and ESR2 (P < 0.001) transcripts were detected in group 1B than in group 2B.