To determine whether Dnmt3a plays an essential role in endometriosis progression, we generated an endometrium-specific Dnmt3a knockout (KO) mouse by crossing floxed Dnmt3a ((Dnmt3af/f)[31] with Progesterone Receptor (PR)Cre/+ mice, in which Cre recombinase is expressed in PR-expressing cells[53]. The gene discussed is PGR; the disease is endometriosis.