Thus, we used transplantation models in immune‐humanized immunodeficient NSG mice (Figure 5A,B) in which we administered recombinant human IL‐34 (rhIL‐34) protein using mini‐osmotic pumps delivering a constant rate of protein and assessed xenogeneic GVHD or human skin transplant rejection. This evidence concerns the gene IL34 and graft versus host disease.