Recombinant FLT3L, such as CDX-301, and FLT3 agonistic Fc fusion proteins have demonstrated the ability to expand dendritic cells (DCs) and hematopoietic precursors in healthy human volunteers (36, 37), which suggest that the FLT3L pathway has the potential to promote T cell-mediated anti-tumor activity. This evidence concerns the gene FLT3LG and neoplasm.