TREC analysis of iNKT cells. Histogram shows mean ± SD of TREC content in indicated subpopulations isolated from (A) thymus (n = 5), CB (n = 8), or (B) PBMCs of healthy adults (n = 7). Comparison is made to naive T cells. Purity of sorted subpopulations was 96% to 99.9%. ^*** indicates that P < .001.