CD19 and Splenomegaly: Acute GVHD induced by C57Bl/6 splenocytes injection to CBF1 mice (F1: CBA×C57Bl/6) was accompanied by splenomegaly, expansion of CD3+ and CD8+, and reduction of CD19+ and CD4+ spleen lymphocytes (Supplementary Figure S4), which are known to be acute GVHD signs [24, 25].