DOCK8 is required for maintenance of peripheral NKT cells in humans and mice. (A) The percentage of αGalCer-tetramer⁺ NKT in CD3⁺ PBMCs from healthy donors (closed circles) and DOCK8-deficient patients (open circles). Statistical significance was tested by the Mann-Whitney U test; *P < .05. (B) Representative plots of lymphocytes from the liver and spleen of WT, heterozygous (HET), and homozygous (CPM) DOCK8^cpm/cpm mice, showing the gating strategy for NKT cells. (C) Absolute numbers of NKT cells in WT, DOCK8^+/cpm, and DOCK8^cpm/cpm mice (circles represent individual mice derived from 4 independent experiments) with statistical significance tested by 1-way ANOVA coupled with Dunn’s multiple comparison test; **P < .01; ***P < .001. (D) NK1.1, CD4, and CD44 expression on NKT cells from (left) WT (dark line) and DOCK8^cpm/cpm mice (filled) and (right) absolute numbers of NK1.1⁺ and NK1.1⁻ NKT subsets. Columns shows arithmetic mean, error bars show standard error of the mean, and statistical significance was tested by Mann-Whitney U test; *P < .05; **P < .01; ***P < .001. Flow cytometry plots are representative of 4 independent experiments.