RAG2 and colitis: The adoptive transfer of WT Tcons (CD4+CD25–CD45RBhi) into immunocompromised mice (recombinant activating gene 2–deficient [RAG2-deficient] mice) induced severe colitis, manifested by a gradual loss of body weight (Figure 3C), a shortened and thickened colon (Figure 3D), as well as bowel hyperplasia, disruption of epithelial cells, and inflammatory infiltrates (Figure 3E).