Pt-Cy preferentially depletes proliferating effector/memory T cells. (A) Representative (out of 10) Ki-67 and HLA-DR expression in PB CD3⁺ T cells at day 3 and day 7 post–haplo-HSCT. (B) Mean ± standard error of the mean (SEM) frequency (n = 22; each dot represents a patient) of Ki-67⁺ T cells with a given differentiation phenotype at day 3 post–haplo-HSCT. ⁺P < .05 vs T_RTE; *P < .05 vs T_N; Wilcoxon test. (C) Mean ± SEM frequency (n = 23) of CD4⁺ and CD8⁺ T cells at day 3 and day 7 post–haplo-HSCT. P < .05 vs day 3; Wilcoxon test. (D) CFSE dilution and CD25 expression by T_N and T_MEM following incubation with auto-APCs or allo-APCs for 3 days. The gate in black identifies CFSE^lo proliferating (ie, alloreactive) cells, whereas that in gray CFSE^hi nonproliferating cells. (E) CD45RO expression by CFSE^lo and CFSE^hi cells, identified as in panel D, originally sorted as T_N (top) or T_MEM (bottom).