Neointima formation and carotid artery remodeling in wild-type mice reconstituted with wild-type bone marrow (wt BM) or CD40^−/− BM. Neointima area and intima-media/ratio was measured at individual levels (100-μm intervals) throughout the ligated artery segments (A and B) and neointimal volume, lumen volume, and total vessel volume were calculated (C), as well as maximal stenosis rate (D). *P < .05 compared with wild-type mice reconstituted with wild-type BM. Neointima formation and stenosis rate was significantly reduced in mice reconstituted with CD40^−/− BM. Error bars represent SEM.