CD3ϵ deficiency but not pTα deficiency blocks the TAL1xLMO1 thymocyte differentiation. Example of flow-cytometry analysis of cell-surface markers on TLMpTαko, TAL1xLMO1, and TLMCD3ϵko thymocytes stained with (A) anti-CD4 and anti-CD8 antibodies, (B) anti-CD25 and anti-CD44 gated on CD3−, CD4−, and CD8− cells, or (C) anti-CD3 gated on CD8+CD4− cells. Percentages are indicated in the quadrants.