Elf-1 deficiency impairs proper iNKT-cell maturation and differentiation. (A-C) Thymocytes and hepatic leukocytes from WT and Elf-1^−/− mice were stained with CD1d/αGalCer tetramer and mAb against TCRβ, CD44, and NK1.1, and then analyzed using flow cytometry. (A) Fluorescence-activated cell sorting plots show the CD44 and NK1.1 expression profile within the tetramer⁺TCRβ⁺ population. Data are representative of 3 independent experiments. Bar graphs depict means ± SD for the proportions (B) and absolute numbers (C) of tetramer⁺TCRβ⁺ iNKT-cell precursors in the thymus based on CD44 and NK1.1 expression (n = 6 for each group; *P < .05; ***P < .001). (D) Thymocytes and liver leukocytes from WT and Elf-1^−/− mice were stained with CD1d/αGalCer tetramer and anti–CD4, and then analyzed by flow cytometry. Histograms show the proportion of CD4⁺ NKT cells within the tetramer⁺TCRβ⁺ population for the indicated organs. Data are representative of 3 independent experiments.