Neointima formation and vascular remodeling in wild-type, CD40^−/−, and CD40L^−/− mice. Representative cross-sections are shown in panels A-C; n = 10, 11, and 10 mice, respectively. Neointima was measured at individual levels (200-μm intervals) throughout the ligated carotid artery segment (D), and neointimal volume was calculated (E). Furthermore, volumes of lumen (F) and total vessel wall (G) were calculated, as well as intima/media ratios (H) and the maximal stenosis rate (I). *P < .05 compared with wild-type mice. Neointima formation in CD40^−/− mice was significantly reduced compared with wild-type mice at all individual levels analyzed throughout the ligated carotid artery.