CHI3L1 and atherosclerosis: Similar to the above study, Batinic et al. [7] detected increased serum YKL-40 in patients with peripheral atherosclerosis, speculating that YKL-40 secreted by macrophages is involved in the formation and rupture of atherosclerotic plaques and that serum YKL-40 levels are closely related to the severity of atherosclerosis.