DS children have less TREC+ lymphocytes than healthy controls, as shown in this box-and-whiskers graphics. The boxes extend from the 25th percentile (x) to the 75th percentile (x) [i.e., the interquartile range (IQ)]; lines inside boxes represent median values. Lines emerging from boxes (i.e., the whiskers) extend to the upper and lower adjacent values. The upper adjacent value is defined as the largest data point ≤x+1.5xIQ, and the lower adjacent value is defined as the smallest data point ≥x-1.5xIQ. Note that no outliers are present in the two groups.