Lack of correlation between magnitude of SIV-specific T-cell responses and the level of T-cell proliferation measured as fraction of Ki67⁺ T cells. (A-B) Comparison of the percent of Ki67⁺ cells in the CD3⁺CD8⁺ (A) or CD3⁺CD4⁺ (B) T-cell subsets in SIV-infected and uninfected animals (^**P < .01, ^***P < .001 as determined by the Mann-Whitney U test.) (C-D) Lack of correlation between the percent of CD3⁺CD8⁺ (C) and CD3⁺CD4⁺ (D) T cells expressing the Ki67 proliferation marker and the magnitude of SIV-specific responses mediated by CD3⁺CD8⁺ (C) and CD3⁺CD8^- (D) T cells. P = ns indicates that the P value of the correlation coefficient is more than .05 (Spearman rank). Error bars in panels A and B indicate standard deviation.