Figure 2: Mucins (MUC2-4) and TFF3 expression depending on severity of CD and UC. The apical surface of the large intestinal epithelium, crypts, goblet cells, and stromal epithelium are lined by the secretory mucin MUC2 and transmembrane MUC3, MUC4, and TFF3 (brown colored). Alcian blue (1.0 and 2.5) positive staining structures (blue, highly glycosylated; purple, medium glycosylated). The photographs are displayed in 400x magnification.