In the past decade, tremendous progress has been made in reducing the incidence of restenosis with the advent of the drug-eluting stent (DES). With "plain old balloon angioplasty," rates of acute and chronic vessel occlusion were unacceptably high at Ϸ30% to 60%, secondary to acute and chronic recoil and constrictive remodeling. The advent of bare-metal stents (BMS) appeared to eliminate the issue of acute and chronic recoil but introduced a new entity, neointimal hyperplasia (NIH), with classical papers unequivocally demonstrating a strong and linear relationship between NIH formation and late lumen loss (LLL). The restenosis rates with BMS were reported to be between 16% and 44%, with higher rates of stenosis attributable to several risk factors, in particular, long lesion length and small vessel caliber. 1 DES were thus conceived as the next step in tackling this iatrogenic entity of NIH, with large-scale reductions in restenosis rates reported at 0% in highly selective lesions and up to 16% in a broader range of patients and lesions with first-generation DES. 1 In contrast to plain old balloon angioplasty and BMS, in which an almost classical gaussian distribution of LLL is seen postprocedurally, the LLL after DES implantation appears to follow a bimodal pattern of distribution ( Figure 1). 2 Despite the significant advances in the technology to reduce DES restenosis, conservative estimates still suggest that the incidence of in-stent restenosis (ISR) requiring target vessel revascularization (TVR), so-called DES failure, to be Ϸ5% to 10%, with one estimate suggesting Ϸ200 000 repeat revascularizations in the United States alone. 3 Whereas the pattern of restenosis in BMS has been shown to be primarily diffuse, with DES it has been demonstrated to be usually focal ( Figure 2) and most commonly located at the proximal DES edge, as demonstrated in Ͼ60% of ISR with either paclitaxel-eluting stent (PES) or sirolimus-eluting stent (SES) implantation. However, over one-fifth of ISR cases remain diffuse, and 10% to 20% are even occlusive. 4 In 2004, the first report of risk factors associated with DES restenosis in patients with the unrestricted use of SES since approval of its CE mark was made by our group. Despite the apparent differences in the distribution of LLL between BMS and DES as previously described, the main message of these and subsequent findings was that the usual patient characteristics, lesion types, and procedural factors incriminated with restenosis in BMS were equally responsible with DES, with diabetes mellitus implicated as one of the strongest risk factors. It should however be emphasized that the "slope" of the distribution of restenosis with DES appears to be much flatter compared with BMS, especially in long lesions and small vessels, highlighting the importance of drug elution in potentially attenuating the NIH response. 3 Histopathologic analyses of in-stent neointima taken by directional atherectomy at the time of reintervention also have been shown to be remarkably similar between BMS ...