We therefore aimed to investigate the OSR1/OSR1 expression in the developed human uterus, and to examine the prenatal and postnatal expression pattern of Osr1/Osr1 in developing MDs and in the endometrium, respectively, and whether its deletion would affect MD development, using WT and genetically engineered mice, including Osr1–/– (9), Osr1FLAG/+, and Osr1-LacZ (8) mice. The gene discussed is OSR1; the disease is myelodysplastic syndrome.