Cell proliferation of Tcon and Treg. The proliferation of Tcon and Treg subsets was determined by expression of Ki67 by flow cytometry. (A) Cell proliferation of Tcon and Treg in healthy subjects (HS) and patients after HSCT. P values indicate comparisons for each category. (B) Cell proliferation of Tcon in healthy subjects and patient subsets based on severity of cGVHD. (C) Cell proliferation of Treg in healthy subjects and patient subsets based on severity of cGVHD. (B-C) P values indicate comparisons among patient subsets. N.S. indicates not significant. (D-E) Relationship between telomerase activity and cell proliferation in Tcon (D) and Treg (E) populations. Correlation was calculated using Spearman rank test.