Human CD45⁺hematopoietic cell and T-lymphocyte development in RG SKI (open dots) and RG SKI IL-6 mice (closed dots). The frequency (A) and number (B) of human hematopoietic (hCD45⁺) cells in the thymus (n = 12-15 per group) were compared at 10, 14, and 18 weeks (C). Representative image of thymus size at week 14. (D) Comparison of frequencies of immature DN (CD4⁻CD8⁻), immature DP (CD4⁺CD8⁺), and mature SP (CD4⁺CD8⁻ and CD4⁻CD8⁺) subpopulations in RG SKI and RG SKI IL-6 mice. (E) Comparison of the absolute numbers of DP thymocytes at different time points. (F) Comparison of absolute numbers of human T-cell commitment progenitor cells in the thymus. (G) Numbers of human CD45⁺ and CD3⁺ cells in BM, spleen, blood (per μL), and LN (left to right) were compared after 10 to 18 weeks (n = 8-12 per group). Because LNs start to appear in ∼15-week-old humanized mice, LN data were only obtained at week 18. Each dot represents 1 mouse. Horizontal bars indicate mean ± SEM. Two independent experiments were performed and the results were pooled. Data were analyzed by one-way ANOVA and unpaired Student t test. Individual P values for posttest are displayed. *P < .05; **P < .01; ***P < .001. DN, double-negative; DP, double-positive; SEM, standard error of the mean; SP, single-positive.