TGFB3 and leiomyoma: We then examined the expression of a number of key genes involved in fibroid pathogenesis by qRT-PCR, WB, and ELISA including two major components of the ECM, namely COL3A1 and FN1; two key regulators of the cell cycle (CCND1 and E2F1); and TGF-β3, a critical pro-fibrotic growth factor known to be overexpressed in fibroids [1,10].