Lymphocyte counts in the 3 groups. Total lymphocytes (A), CD19⁺ B cells (B), NK cells (C), CD4⁺ T cells (D), and CD8⁺ T cells (E) in HC group (white plots), DC group (light gray plots), and HLH group (dark gray plots). Each point represents an outlier (error bars, 10th and 90th percentiles). *P < .05, ***P < .001, ****P < .0001 by Mann-Whitney U test.