Consistent with CD8+ T-cell mediated GVHD in this model, numbers of CD8+ T cells were higher in spleen on day 26 after allo-HSCT (Fig 3B) while numbers of donor spleen-derived CD4+ T cells in the spleen were significantly lower on day 10 compared with syn-HSCT recipients. This evidence concerns the gene CD4 and graft versus host disease.