Thus, we next genetically depleted TNF in myeloid cells (M-TNF−/−× Rag1−/−; TNFf/f×Mlys-Cre×Rag1−/−) and in epithelial cells (EC-TNF−/−×Rag1−/−; TNFf/f×Vil-Cre×Rag1−/−) in Rag1−/− mice and induced colitis by transfer of naive T cells from WT mice. Here, RAG1 is linked to colitis.