miR-17-92 expressed on donor T and B cells contributes to the pathogenesis of cGVHD. BALB/c (H2K^b+) mice were lethally irradiated and transferred with 0.5 × 10⁶ splenocytes plus 2.5 × 10⁶ TCD-BM from Cre⁻, CD4Cre⁺, CD19Cre⁺, and CD4 Cre⁺CD19Cre⁺ miR-17-92^flox/flox mice on a C57BL/6 background. Survival (A) and clinical scores of cGVHD manifestations (B) were monitored weekly. Representative flow figures (C) and percentage (D) of CD4⁺CD8⁺ cells in recipient thymus are shown on gated donor cells 60 days post-BMT (N = 15-20 mice per group). (E) Pathology scores in recipient skin are shown 60 days post-BMT (N = 4-5 mice per group). *P < .05; **P < .01; ***P < .001.