MSX1 and Infertility: Based on RT-qPCR analyses, the retained PGR signaling was substantiated by increased mRNA levels of PGR responsive genes, such as Pgr, Ihh, Msx1 and Msx2. Thus, it is possible to postulate that FOXO1 is involved in the downregulation of epithelial PGR, which accounted for the infertility in mice.