Dll4Fc slightly promotes erythroid differentiation. (A) Kinetic analysis of erythroid differentiation from human cord blood CD34⁺ cells cultured onto control or Dll4Fc-coated wells in the presence of Hu EPO, Hu SCF, and HuIL-3. Flow cytometric analyses were performed at days 5, 7, 10, 12, 14, and 17. Histogram representation of cytometric analysis for CD36 and GPA markers (mean ± SEM from 3 independent experiments). (B) Notch1 and 2 expression is downmodulated throughout erythroid differentiation. Analysis by quantitative RT-PCR of the expression levels of Notch1 and Notch2 in sorted cell populations at day 11 throughout erythroid differentiation. mRNA expression of each gene was normalized to that of HPRT mRNA and calibrated to the gene:HPRT ratio in HEL cells. Results were obtained from 3 independent experiments.