There is one clinical trial.
The objective of this study was to investigate the relationship between single nucleotide polymorphism of chitinase 3-like 1 and human asthma.
The C-allele of the -131 C→G (rs4950928) polymorphism of CHI3L1 has been shown to associate with bronchial hyperresponsiveness and reduced lung function.
In contrast to preliminary studies, the investigators predict the rs4950928 G allele, and not the C allele, was found to be associated with asthma.