C1QTNF9 and endothelial dysfunction: Previous studies have shown the strong association between the serum CTRP9 and the coronary atherosclerosis [12] and further elucidated the great potential of CTRP9 in cardiovascular protection via regulating endothelial dysfunction [11], modulating metabolic pathways [13, 14] and inhibiting vascular inflammation [15], which were thought as the important mechanisms influencing the process of CCG [6].