Furthermore, aprevious experimental study confirmed that the absence of the protease inhibitor Cys-C in inflammatory cells resulted in a larger plaque area and/or promoted atherosclerosis in an atherosclerotic mouse model.30,31 This is in contrast to our results showing that elevated Cys-C is associated with the severity of CAD. A possible explanation is that there is a negative feedback loop in the regulation of Cys-C to counter act the increased elastolysis activity.Furthermore,a renal mechanism might be an other potential link between increased Cys-C and CAD.