In contrast, a significant association between the CHI3L1 gene variants and YKL-40 levels, but the absence of an association with either atherosclerosis-related quantitative traits or PAD for the CHI3L1 gene variants suggests that the influence in baseline YKL-40 levels due only to YKL-40 promoter polymorphisms may not be large enough to alter the risk of atherosclerotic cardiovascular disease. This evidence concerns the gene CHI3L1 and peripheral arterial disease.