While both cystatin C and left ventricularejection fraction (LVEF) revealed established prognostic efficacy in coronaryartery disease (CAD), the relationship between cystatin C/left ventricularejection fraction ratio (CLR) and adverse clinical outcomes among patients withCAD following percutaneous coronary intervention (PCI) remains obscure, to date.Therefore, we sought to assess the predictive efficacy of CLR among CAD patientswho underwent PCI in current study. The gene discussed is CST3; the disease is coronary artery disorder.