Phenotypic analysis of CD4-expressing cells derived from human cord blood HSCs cocultured on OP9 control cells or OP9-DL1 cells. CD34⁺CD38^– cells sorted from human cord blood were cocultured with OP9-control (A) or OP9-DL1 (B) stromal cells for 40 days. Cells derived from coculture with either OP9-control or OP9-DL1 stromal cells were gated for CD4⁺ expression and subsequently examined for the expression of T-cell markers CD8 by CD3, or myeloid markers CD33 by CD14 and MHC class II. The percentage of gated cells is given within the histogram and contour plots. As a reference, the expression of CD4 by CD8 is presented from day 40 cocultures on OP9-control (A, top) or OP9-DL1 (B, bottom) stromal cells.