Notably, G-CSF administration significantly decreased the expression of adhesion molecules involved in GVHD on naïve CD4+ and CD8+ T cells in BM grafts and led to polarization of BM naïve CD4+ and CD8+ T cells from Th1 to Th2 phenotype, which may lead to a lower incidence of GVHD (38, 39). This evidence concerns the gene CD4 and graft versus host disease.