The role of PAI-1 in leiomyoma fibrosis was demonstrated by the observation that TGF-β3 induced protein expression of PAI-1 in human uterine leiomyoma cells which was inhibited by antifibrotic compound, 1,25-Dihydroxyvitamin D3 [35]. The gene discussed is SERPINE1; the disease is uterine corpus leiomyoma.