CD4 and mastocytoma: In the past, it was shown that the graft treatment with the anti-human CD4 antibodies MAX.16H5 IgG1 (murine) or IgG4 (chimeric) was able to prevent GVHD in a xenogeneic NSG HSCT model (27) and also to preserve the GVL effect in a murine mastocytoma model (MAX.16H5 IgG1) (26).