In wt mice with chronic colitis, IL-23a, IL-13, NF-kB2, PTGS1, SMAD3 and SMAD7 (P≤0.05) were significantly down-regulated, with the largest variations affecting the expression of IL-23a and IL-13 (100- and 10-fold) (Figure 6A). This evidence concerns the gene SMAD7 and Chronic colitis.