Analysis for the presence of T-cell progenitors generated in vitro. (A) Flow cytometric analysis for the expression of CD7 and CD45RA from HSC/OP9-DL1 cocultures harvested at the indicated time points, including at day 0 before the start of coculture. (B) Flow cytometric analysis of CD7 and CD34 expression from HSC/OP9-DL1 cocultures harvested at days 4, 6, and 8 (top row), with CD45RA expression shown for cells gated as CD34⁺CD7⁺⁺ (bottom row). Data are representative from 3 independent cocultures. Numbers in plots indicate percentage of cells within each quadrant; RCN, relative cell number.