IL-7Rα and γc expression by CD8⁺ T-cell subsets in elderly and young subjects. IL-7Rα and γc expression was measured on naive (CD45RA⁺CCR7⁺), central memory (CM, CD45RA⁺CCR7⁺), effector memory (EM, CD45RA^-CCR7^-), and EM_CD45RA+ (CD45RA⁺-CCR7^-) CD8⁺ T-cell subsets in healthy elderly and young subjects using flow cytometry. (A) Representative histograms of IL-7Rα (shaded) and isotype control (open) staining. MDFI of IL-7Rα (B) and γc (C) staining was compared between the elderly (○, n = 10) and the young (•, n = 10). (D) The frequency of IL-7Rα^high and IL-7Rα^low cells in the EM_CD45RA+ CD8⁺ T-cell subset was compared between elderly (○, n = 10) and young (•, n = 10) subjects. P values were obtained with the Mann-Whitney U test.