Collagen deposition was clearly more pronounced in chronic three‐cycles DSS colitis compared with acute colitis, in both WT and RAG‐1−/− mice as shown by MSB collagen quantification (P = .003 and P < .001, respectively) and hydroxyproline measurements (P = .003 and P < .001, respectively; Figure 1J‐R). Here, RAG1 is linked to colitis.