Higher CD4⁺ T-cell frequencies are observed in cGVHD but not skin aGVHD. Flow cytometric analysis of fresh lymphocytes isolated from 4-mm punch-skin biopsies after collagenase digestion. Shown is a comparison of CD4 (ECD) and CD8 (AmCyan) frequencies (A), naive (NA, CD45RA⁺, AF700), CCR7⁺ (FITC), EM (CD45RA⁻CCR7⁻), central memory (CM, CD45RA⁻CCR7⁺), and EM RA⁺ (RA⁺CD45RA⁺CCR7⁻) frequency (B), and CXCR3⁺(PE) expression (C) by CD3⁺ T cells in the skin of patients with aGVHD (n = 10) and cGVHD (n = 9). Data are expressed as the median frequency of CD3⁺ T cells with bars illustrating the interquartile range (A-B) and as the mean frequency with bars illustrating SEM (C-D). *P < .05 and **P < .005 by the Mann-Whitney U test.