(a)  OCT
(b)  HE
(c)  Macrophage
(d)  SMC
Figure 4: Representative cross-sectional images of the balloon-injury group and needle-injury group. (a): a concentric plaque with a lipid-rich core and thick fibrous cap from the balloon-injury group and eccentric plaque with a lipid-rich core and thin fibrous cap from the needle-injury group; (b): corresponding histology sections with a similar shape from the two injury groups; (c): immunostaining for macrophages by anti-CD68 antibody (arrows in (c)), which demonstrate greater accumulation of macrophages in the needle-injury group relative to the balloon-injury group; (d): immunostaining for smooth muscle cells (SMCs) by anti-SMC α-actin antibody. The fibrous cap of the plaque in the balloon-injury group contains more SMCs compared with that in the needle-injury group. The original magnification in figure (b) is ×40, whereas in (c) and (d) it is ×100.