Figure 4: Reduced expression of in atherosclerotic (A) region of aorta as compared to the adjacent nonaffected (N) region. From (a) to (c): detection of proliferating cells in an exemplar biopsy of an artery by an antibody against human nuclear protein Ki-67 (a). Red arrows highlight some proliferating nuclei (black staining), while blue arrows exemplify nonproliferating nuclei (light grey). Staining with antibodies against smooth muscle α-actin (b) and against (c). Scale bars, 50 μm.