Notably, studies in mice suggest that G-CSF may separate GVHD and graft-versus-leukemia (GVL) responses by exerting suppressive effects on CD4+ T cells, that are implicated in GVHD, while preserving the cytolytic pathways of CD8+ T cells that are critical for effective GVL [44]. This evidence concerns the gene CD4 and graft versus host disease.