Effect of RAS blockers on erythroid cell proliferation. Percentage of mitotic erythroid cells in embryos treated with vehicle only (c, n = 8, ▪), fosinoprilate (Fos, n = 6, ), or Sar1-Ile8-Ang II (Sar, n = 7, □). Each bar is a mean ± SEM. **P < .002.