The cell line has been proven to have a similar diploid karyotype to normal nasal epithelial cells.27 It has also been shown to have some similarity in terms of the expressed surface cytokeratins,28 and it produces a mucoid material that is visible on the cells apical surface.26 To date, the cell line has only been validated as a model to study the regulation of TGF-β biology in house dust mite–related allergic rhinitis.29 The neoplastic source of these cells perhaps explains the mixed epithelial and mesenchymal phenotype and growth pattern in cell culture. This evidence concerns the gene TGFB1 and allergic rhinitis.