CLCA1 and ulcerative colitis: Whole genome expression analysis revealed that a group of genes was differentially regulated in the epithelial organoid cultures (EpOCs) and differentiated EpOCs (d-EpOCs) in patients with ulcerative colitis,84 including a marked down-regulation of hCLCA1, which is a major component of the mucus produced mainly by secreting cells of the distal digestive tract.77