Two YKL-40 SNPs, located in the promoter (rs871799) and in the exon 5 (rs880633) region, respectively, were found to modulate age-adjusted lung function in CF patients (longitudinal FEV1age-adjusted at 20 years according to the method described previously by Schluchter et al. [19] (Table 2 and Figure 2A). The gene discussed is CHI3L1; the disease is cystic fibrosis.