CHI3L1 and endothelial dysfunction: Subsequently, several clinical studies have reported that an elevated serum CHI3L1 level compared with that of healthy controls is associated with an increased risk of hypertension, endothelial dysfunction, vascular injury, angiographic lesion progression, carotid atherosclerosis, peripheral artery disease, atherosclerosis, large-artery atherosclerotic stroke, coronary artery disease, and cardiovascular complications in patients with diabetes, heart or kidney transplant recipients, and patients with sleep apnea syndrome86,130–151, suggesting CHI3L1 as a diagnostic marker for CVD.