ESR2 and polycystic ovary syndrome: As shown in Figure 1A, the abundance of mRNA in nuclear estrogen receptors (ERs) (ESR1, ESR2 isoforms ESR2v1, ESR2v2, ESR2v4 and ESR2v5) was not different between PCOS and control groups, whereas that of the progesterone receptor (PR) gene was significantly higher by 1.53-fold (p = 0.044) in the PCOS group (Figure 1A).