Expression of IL-15Rα, IL-2/15Rβ, and IL-21R by EM and EM_CD45RA+ IL-7Rα^high and IL-7Rα^low CD8⁺ T cells in elderly and young subjects. PBMCs from healthy elderly and young subjects were stained with antibodies to CD8, CCR7, CD45RA, IL-7Rα, IL-15Rα, IL-2/15Rβ, IL-21R, or isotype antibodies. The expression of IL-15Rα (A), IL-2/15Rβ (B), and IL-21R (C) was determined by gating on IL-7Rα^high and IL-7Rα^low cells in EM and EM_CD45RA+ CD8⁺ T-cell subsets. Results are representative data from 4 separate subjects in each group.