a, Phospho-ERK1/2 in OT-I double-positive thymocytes from mice stimulated with SIINFEKL or RTYTYEKL. White symbols, untreated; grey symbols, CsA-treated. b, Egr1 upregulation in OT-I double-positive thymocytes stimulated with SIINFEKL or RTYTYEKL. c, CD69 upregulation in OT-I double-positive thymocytes after 4 h of stimulation. Δ indicates the percentage difference in CD69 thymocytes stimulated by APCs only or by peptide-pulsed APCs. Solid lines, APCs plus peptide; grey areas, APCs only. d, CD4 and CD8 expression in thymocytes from mice of the indicated genotypes. e, Percentage of CD4 single-positive expressing Vβ chains reactive or not to endogenous superantigens (squares show results for individual mice; bars show medians; n≥3). White symbols, untreated control; light grey symbols, Bim-deficient; dark grey symbols, Bim-deficient and CsA-treated. f, Percentages (numbers shown in each panel refer to the percentage of cells in the indicated interval) and absolute numbers of HY+ CD8 single-positive CD24low cells in mice of the indicated genotypes (squares show results for individual mice, bars show means; n≥4). White symbols, untreated; grey symbols, CsA-treated.