Mito‐transfer decreases oxidative stress in CD4+ T cells from old mice. A) Heatmap of proteins related to cellular antioxidants and mitochondrial detoxification in CD4+ T cells from old mice with and without mito‐transfer (4h). Flow cytometry histograms and scatter plots of the relative MFI of B) thiol‐tracker violet, C) CellROX Deep Red, and D) MitoSOX Red stained CD4+ T cells from young, old mice and CD4+ T cells from old mice after mito‐transfer. E) EPR spectrum and H) bar graphs of CD4+ T cells probed with Mito‐Tempo‐H. 4–5 mice per group, with experiments repeated at least once, p ≤ 0.05 = *, p ≤ 0.01 = **, p ≤ 0.001 = *** and p ≤ 0.001 = ****, using one‐way‐ANOVA where appropriate.