CD8⁺ subset composition during and after intensive chemotherapy. CD8⁺ subsets were measured in the peripheral blood at serial timepoints using two and three color flow cytometry. Mean values ± standard error of mean (SEM) for all patients analyzed at each timepoint are shown. (▪) CD8⁺CD3⁺; (▧ CD8⁺CD28⁺; (▤) CD8⁺CD28⁻; (□) CD8⁺CD57⁺; (▧) CD8⁺CD45RA⁺.