The glycoprotein YKL-40, also named chitinase-3-like-1 (CHI3L1), is an inflammatory marker, found to be elevated in conditions characterized by low-grade inflammation, such as myocardial infarction [9, 10], and stable coronary artery disease [11], type 2 diabetes [12, 13], and morbid obesity [14, 15]. Here, CHI3L1 is linked to morbid obesity.