Dose-dependent induction of lymphoid differentiation. CD34⁺CD38^– cord blood precursors were incubated with increasing Delta1^ext-IgG densities or human control IgG and analyzed by FACS at day 21 for CD7 and CD34 expression (A), day 10 for CD25 and CD44 expression (B), and day 14 for intracellular CD3ϵ expression (C). Control human IgG is designated in the figures as control or Delta1^ext-IgG at 0 μg/mL. Data are representative of 3 independent experiments. Numbers in corners of dot blots are the percentage of gated events within that quadrant (R² = 0.95; P = .004).