DOCK8 is required for maintenance of the thymic resident NK1.1⁺NKT cells. (A) Total TCRβ⁺αGalCer-tetramer⁺ thymic NKT cells in WT (closed circles) and DOCK8^cpm/cpm (CPM, open circles) mice gated on CD8-negative live lymphocytes. (B) Total thymic TCRβ⁺αGalCer-tetramer⁺ NKT cells at different stages of development in WT (closed circles) and DOCK8^cpm/cpm (CPM, open circles) mice. (C) BrdU labeling of thymic NKT cell subsets in WT (open columns) and DOCK8^cpm/cpm (CPM, filled columns) mice (n = 5 for each) 9 days after its addition to drinking water. Columns shows arithmetic mean, error bars show standard error of the mean, and statistical significance was tested by unpaired t test; *P < .05; **P < .01; ***P < .001. BrdU labeling data are representative of 3 independent experiments.