Serum derived BMP9 promotes proliferation of IOSE397 cells and ovarian cancer cell lines. A, IOSE397 cells were incubated for 1 hour with increasing concentrations of ALK1ecd −/+ BMP9 (5ng/ml) in 5% FBS media. Western blots were performed with indicated antibodies. B, cells were incubated −/+ ALK1ecd (16 F.M.E.) in 5% FBS (IOSE397) or 10% FBS (TR175 and OVCA433) and counted at day 6. Data are displayed as percent of untreated cells (mean ± S.D, n≥3). C, IOSE397 cells were incubated for 1 hour with increasing concentrations dorsomorphin (Dm) −/+ BMP9 (5ng/ml) in 5% FBS media. Western blots were performed with indicated antibodies. D, Cells were incubated −/+ dorsomorphin (Dm, 1μM) in the same conditions as in C and counted at day 4. Data are displayed as percentage of untreated samples (mean ± S.E.M, n=3). * = P< 0.05.