Chitinase-3-like protein (CHI3L1), also known as cartilage glycoprotein 39 (YKL-40), is a carbohydrate-binding lectin with a preference for chitin [, ]. It is a a member of the glycosyl hydrolase 18 family, but lacks hydrolytic activity, probably because of a single amino acid substitution in the catalytic centre region []. Chitinase-3-like protein is implicated in cell proliferation and angiogenesis and has been shown to stimulate migration and adhesion of cultured vascular smooth muscle cells [, ]. It is secreted by various immune, connective tissue and cancer cells and it is associated with inflammatory disorders, like asthma and atopy [, , ].
