MUC5AC and colorectal carcinoma: However,compromised integrity of the inner mucus layer that functions to shield the epithelium from luminalbacteria might accelerate the progression of CRC and inflammatory bowel disease: In animal models,mucin gene defects can lead to intestinal cancers or microbiota-dependent acute colitis (Velcichet al, 2002; Fu et al,2011; Bergstrom & Xia, 2013).