However, the inflammation increased intestinal tumorigenesis in Apc mutant mice by introducing Muc2 deficiency to the mice [21], and loss of cyclin dependent kinase inhibitor p21WAF1 enhanced intestinal tumor formation in Muc2−/− mice [22], Our current study further showed that Muc2 deficiency mice spontaneously develop chronic colitis at their early age (<3 moths), whose histopathology was similar to ulcerative colitis in patients. This evidence concerns the gene MUC2 and ulcerative colitis.