To determine whether the inflammatory response is equally involved in the pathogenesis of restenosis after coronary stenting and directional coronary atherectomy, we assessed restenotic lesions with immunohistochemical methods. Levels of C-reactive protein and macrophages were greater in patients with in-stent restenosis than in those with restenosis after directional coronary atherectomy. This suggests that the inflammatory response is more involved in the pathogenesis of in-stent restenosis than in restenosis after directional coronary atherectomy.