Macrophages drive the formation of atherosclerotic plaques by stimulating inflammation and the accumulation of LDL. Nazari-Jahantigh et al. investigated how microRNAs influence the behavior of macrophages in atherosclerotic plaques. They found that miR-155 repressed the expression of the anti-inflammatory protein Bcl6 in macrophages and enhanced plaque formation. Here they performed immunostaining to visualize macrophages in atherosclerotic plaques in the carotid arteries of mice with (left) and without (right) Bcl6.