Finally, Demaria et al. [39] demonstrated the abscopal effect, the reduction in tumor growth outside the field of radiation, in mice who received RT and growth factor Flt3-Ligand (Flt3-L), but not Flt3-L or RT alone, or in mice with T cell deficiency, emphasizing their role in this process. This evidence concerns the gene FLT3LG and congenital T-cell immunodeficiency.