AHSCT induces long-term perturbation of naive T-cell homeostasis. Phenotypic analysis of naive and memory peripheral blood T cells was performed by multiparameter flow cytometry using conjugated antibodies against CD3, CD45RA, and CD27. The frequency of proliferating naive (A) and memory (B) T cells was determined by quantification of Ki-67 nuclear expression. The solid horizontal lines represent the average Ki-67⁺ frequencies for each group. Statistical significance was calculated by the 2-tailed Student t test and is shown on top of graphics. N.S. indicates not significant.