CHI3L1 and acute coronary syndrome: OPG associates with acute coronary syndromes and CVD-related mortality45,46 together with high levels of GDF15,47,48 MMP12,15 and CHI3L1,49 all co-expressed in module 6 by WCGNA.48,50 Of note, endotype 4 is characterized by low soluble Interleukin 6 receptor circulating levels, a known pro-inflammatory biomarker.51 Analysis by WCGNA identified 6 modules of co-expressed proteins including biomarkers whose relative concentration differed across endotypes.