Ldlr−/− mice were transplanted with bone marrow from WT or Fpr2−/− bone marrow. (A) Aortic root sections were stained with hematoxylin and eosin (H&E) (left), and cap thickness was quantified (right). Scale bar, 100 μm. (B) Collagenase activity was quantified in aortic root sections using fluorescence microscopy and image processing. (C) Superoxide (DHE) was assessed by fluorescence microscopy. Data are for individual mice, with means shown as horizontal lines (n = 5 separate mice, two sections per mouse). **P < 0.01 versus all other groups, one-way ANOVA with post hoc Tukey analysis.