By contrast, we observed prominent WGA staining in the lumen, particularly at the goblet cell outlet of untreated CF intestinal crypts, in addition to staining in goblet cells (Fig. 3a), WGA staining of treated CF samples showed that the majority of mucin remained within the goblet cells similar to that observed in wild type, while the number of strong mucin staining cells in the lumen was highly reduced compared with untreated CF mice. This evidence concerns the gene MUC5AC and cystic fibrosis.