DAB/IL2 transiently depletes all analyzed CD4+ T cell subsets. Whole blood was collected from 10 patients throughout the first cycle of DAB/IL2 and analyzed for CD4+/CD25HI/Foxp3+ co-expression by flow cytometry as described in the Figure 2 legend and Methods section. The absolute concentration of CD4+/CD25- (black), CD4+/CD25+ (red) and CD4+/CD25HI (green) T cells (A) and of CD4+/CD25HI/Foxp3- (black) and CD4+/CD25HI/Foxp3+ (red) T cells (B) were quantified by multiplying the percentage of anti-CD4, anti-CD25 and/or anti-Foxp3 fluorescence-positive cells within the lymphocyte forward/side scatter gate by the absolute lymphocyte concentration determined using an automated hematology analyzer. The percent control of each sample was calculated by dividing the absolute cell concentration on the indicated day of treatment with the cell concentration on day 0 prior to DAB/IL2 administration (× 100). Data are represented as averages ± standard error of the mean (n = 10 patients).