been extensively studied in relation to their pathological implication in the disease process. Mucins are under investigation as possible diagnostic markers for malignancies and other disease processes in which they are most commonly over- or mis-expressed. Abnormal deposits of mucin are responsible for the non-pitting facial edema seen in untreated hypothyroidism. This edema is seen in the pretibial area as well. Non-vertebrate mucins Beyond the better-studied vertebrate mucins, other animals also express (not necessarily related) proteins with similar properties. These include: Drosophila is known to express mucin proteins containing PTS-rich repeats. Trypanosoma cruzi express cell-surface mucins (PF01456). See also Bovine submaxillary mucin coatings Verotoxin-producing Escherichia coli References Further reading External links Glycoproteins