Percutaneous transluminal coronary angioplasty has revolutionized the management of patients with coronary artery disease.Unfortunately,the procedure 's utility is limited by a frequent complication: restenosis.Coronary stenting prevents the elastic recoil and negative remodeling that can occur after angioplasty but,by inciting varying degrees of intimal expansion,it can also produce arterial renarrowing, known as in-stent restenosis (ISR).The precise mechanisms involved in the pathogenesis of ISR are incompletely understood.The recent introduction of drug-eluting stents (DESs)may help prevent ISR. However,DESs have not been universally successful,and they may introduce new complications that require further refinement.This review summarizes the current understanding of the pathogenesis of ISR and provides an objective overview of DESs.