BDNF was originally discovered in the nervous system as a stress responsive messenger (Larsen et al., 2010; Panossian et al., 2018), but has recently shown to be related to human reproductive diseases including polycystic ovary syndrome, infertility, and impaired ovarian oocyte development (Wu et al., 2012a; Russo et al., 2012; Sadeu et al., 2012). Here, BDNF is linked to polycystic ovary syndrome.