Expansion of the γδ and DN αβ T cell populations in Itk-deficient mice. Five WT and Itk-deficient mice (C57BL/6 background) were studied in two batches of experiments. (A) Frequencies of αβ and γδ T cells in the thymus (Thy) and spleen (Spl). (B) Phenotypes of γδ T cells. CD24 staining was performed for only three of the five mice. (C) αβ T cell subsets. (D) Phenotypes of DN αβ T cells. Bars represent the mean and SEM. Statistical significance was determined for differences between WT and Itk-deficient mice. n.s., not significant. *, P < 0.05, two-tailed Wilcoxon’s rank sum tests with FDR adjustment.