Enforced expression of activated Notch1 drives cellular expansion of β-selected pre-T cells and increases αβ T-cell generation. (A) Flow cytometry analysis of CD3 versus TCRαβ expression on electronically gated GFP⁺ cells generated from ICN1-transduced (ICN1) or mock-transduced (GFP) β-selected DP CD3^lo thymocytes after 14 days in FTOC. (B) Total cell numbers of GFP⁺-gated cells recovered from ICN1-transduced (▪) or GFP-transduced (○) β-selected thymocytes at the indicated time points in FTOC. Absolute numbers were normalized to 2 × 10³ GFP⁺ transduced cells/lobe. Results are representative of 3 experiments.