Syk activation during cGVHD. (A) B cells were purified from the spleens of healthy control (BM only) or cGVHD (BM + T) mice and stimulated with anti-IgM at 5 μg/mL. Splenocytes from B10.BR mice transplanted with B6 BM and low numbers of T cells were analyzed for pSyk at Y348 after ex vivo stimulation by 5 μg/mL of anti-IgM. (B) Cumulative expression of phosphorylated Syk. *P < .5. Error bars represent standard error of the mean (SEM); n = 8 representative data from 2 experiments.