From the point of view of humanized mice construction, prkdc mutation was more suitable than Rag2, and (3) except for T-cells, B-cells, NK cells, neutrophils, macrophages, and cytokines could also cause a reaction of graft-versus-host disease, though the Rag2/IL2rg mutation reduced the number of neutrophils, lymphocytes in this study, residual granulocytes, macrophages, and cytokines might make it difficult for grafts to survive in mice. Here, RAG2 is linked to graft versus host disease.