Fig. 3

IL-21 enhances CD4⁺ and CD8⁺ T_SCM frequencies. Naïve T cells from healthy donors (n = 6) were cultured for 10 days with short (solid black line) or long (solid grey line) costimulation and in the presence (black dashed line) or absence (grey dashed line) of IL-21. a, b Frequencies of CD4⁺ and CD8⁺ T_SCM (mean ± SEM) are shown in (a) and (b), respectively. c, d Frequencies of CD4⁺ and CD8⁺ Total T_SCM (T_SCM + T_SCM-like) (mean ± SEM) are shown in (c) and (d), respectively. *p < 0.05; **p < 0.01; ***p < 0.001