Cell proliferation and apoptosis in the endocardial cushion at E12.5. (A) Representative immunohistological staining of pHH3 (nucleus) and cleaved caspase-3. (B and C) Quantification of pHH3+ cells (cell proliferation) and cleaved caspase-3+ cells (apoptosis) in relation to total endocardial cushion cells. *P < 0.05, **P < 0.01 vs. untreated control, †P < 0.05 vs. untreated diabetes. Scale bar is 50 μm.