The effect of BMP-4 in OH-2 cells does not wane with time.

Cellular viability in OH-2 cells was measured daily by annexin V–FITC and PI flow cytometry after incubation without cytokines or with 10 ng/mL BMP-4 or 1 ng/mL IL-6, as indicated. Data are expressed as the percentage of viable cells—that is, the percentage of cells in the lower left quadrant of dot plots, as exemplified in Figure7.