To determine whether Dnmt3a plays an essential role in endometriosis progression, we generated an endometrium-specific Dnmt3a KO mouse by crossing floxed Dnmt3a (Dnmt3af/f) (22) with PRCre/+ mice, in which Cre recombinase is expressed in PR-expressing cells (21). This evidence concerns the gene DNMT3A and endometriosis.