Intriguingly, the strict IFNγ dependent colitis induction in the anti-CD40 colitis model in Rag1−/− mice is also associated with a strict dependence on ILC as inducers of colitis while in the presence of colitogenic CD4 T cells ILC and IFNγ are not critical for the induction and progression of CD4 T cell transfer colitis. This evidence concerns the gene RAG1 and colitis.