Relationships between age and T-cell subsets after intensive chemotherapy. The absolute number of each lymphocyte subset was measured in the peripheral blood of patients approximately 3 months after completion of chemotherapy. Correlation coefficient was calculated by the Spearman rank correlation method. (A) CD8⁺CD3⁺ cells. (B) CD4⁺CD3⁺ T cells. (C) CD8⁺CD45RA⁺ cells. (D) CD4⁺CD45RA⁺ cells.