We had shown earlier that ND human (hu) IgG4 specific for huCD4 (clone CH5g5) and huCD8α (clone CH9d2) induces egress of pathogenic CD4+ and CD8+ T cells from inflamed tissues in NRG.PBL humanized mice, which develop xenogeneic graft-versus-host disease (xGVHD) (27). This evidence concerns the gene CD4 and graft versus host disease.