Mice lacking FKBP52 displayed female infertility and several defects in male sexual development, which is in line with the role of FKBP52 in hormone signaling, especially as an PR and androgen receptor (AR) regulator (Cheung-Flynn et al., 2005; Sivils et al., 2011; Guy et al., 2016). Here, FKBP4 is linked to female infertility.