CD4 and graft versus host disease: In cGVHD, we also show that prophylactic administration (10 mg/kg) of Ibrutinib was able to restore the absolute B-cell number (Fig 4H) in B10.D2→BALB/c model, as well as the thymic CD4 and CD8 double-positive T cell number in the DBA/2→BALB/c model (B in S3 Fig) reflecting improved immune reconstitution and decreased severity of GVHD pathogenesis [5].