Review

as s a rotein YKL-40 have been associated with severe asthma, ere ses os ease entity [3]. Thus, an understanding of the complex is an essential component of fungi, house-dust mites, exo-skeletons of crabs, shrimp and insects, parasitic nematodes, Mack et al. Molecular and Cellular Pediatrics (2015) 2:3 DOI 10.1186/s40348-015-0014-6chitin has important immunologic effects in vitro and in vivo, initially highlighted by Shibata et al. who Full list of author information is available at the end of the articleimmunological and pathophysiological implications of chitin-chitinase interactions in the human body is of high relevance for identifying new biomarkers and thera-peutic targets for fungal diseases and other conditions, and digestive tracts of many insects [1]. Chitin protects these microbes from their environment, and its turnover is regulated by biosynthesis and degradation through endogenous chitinases. The first immune stimulatory activity of chitin and chitin derivatives in mammals was discovered and exten-sively explored in the middle to late 1980s, as reviewed recently [2,1]. These early studies clearly indicated tha