Earlier studies in fibroid research demonstrated that cultured leiomyoma cells responded to 100 ng/mL of UPA (also known as CDB-2914; CDB-2914 (17α-acetoxy-11β-[4-N,N-dimethylaminophenyl]-19-norpregna-4,9-diene-3,20-dione) by regulating progesterone receptor (PR) isoforms [34]. This evidence concerns the gene PGR and leiomyoma.