While the pathogenic role of chitinases/CLPs in (dys)regulation of inflammation in CF airways remains poorly understood, observations in lungs from Scnn1b-transgenic mice demonstrate that some proteins of the chitinase/CLP family, such as Ym1 and Ym2, are expressed at such high levels that they precipitate and form sharp crystals often greater than 100 μm in size [54]. This evidence concerns the gene SCNN1B and cystic fibrosis.