Cross-sectional analysis of Treg cell subsets in HL patients. Box and whisker plots summarizing the percentages of the mean (horizontal bar), standard error (box), and standard deviation (whiskers) of Treg cells in HL patients at diagnosis, in remission, and in randomly chosen healthy laboratory controls. The percentage of positive cells with each phenotype is shown on the vertical axis, and the P value and number of samples are indicated above and below each plot, respectively. P values were generated using the Mann-Whitney test.