Smooth muscle cells cultured from the myometrium showed no significant induction of SFRP1 mRNA in response to treatment with E2 and/or progesterone.  Conversely, cells cultured from leiomyomas showed significant dose-dependent induction of SFRP1 mRNA in response to treatment with E2; however, progesterone had no effect on SFRP1 even when coapplied with E2.