ECP is detected in nasal mucosa in association with damaged epithelium [48] , in damaged corneal epithelium [96] as well as in BALF (at 40 ng/mL, table 1) [97] . The function of ECP has been assessed using several assays in the view of the presence of the eosinophil in the airways. Both destructive and non-destructive consequences have been found when analyzing various concentrations of the protein in interaction with the epithelium. High levels of ECP (5.4 μM/103 μg/mL) caused exfoliation of guinea-pig mucosal cells after 6 hr incubation with tracheal epithelium [79] . Confluent primary human corneal epithelial cells incubated with 0-100 μg/mL ECP, displayed a concentration-dependent gradual increase in morphological change and with the highest concentration, 100 μg/mL, being cytotoxic [98] . Lower concentration of the ECP (2.5 μg/mL) caused release of respiratory glycoconjugates (marker of mucus secretion), with a peak after 1 hr, from feline tracheal B. Allergic asthma A. Healthy control Figure 4 Eosinophil granulocytes in the bronchial mucosa. Sections of bronchial biopsies from (A) a healthy control or (B) an individual with allergic asthma were stained with ECP antibody visualizing eosinophils in the mucosa. The figures show that only a few eosinophils are present in the tissue of the healthy control, but many eosinophils accumulate in areas of reduced epithelial integrity in a specimen from a patient with allergic asthma. Original magnification ×420; Mayer's haematoxylin.