For years, researchers have debated whether the enzyme lipoprotein-associated phospholipase A2 (Lp-PLA2), produced by inflammatory cells, is a 'good guy' or 'bad guy' in atherosclerosis. Work in pigs provides strong support for the view that Lp-PLA2 promotes the formation of atherosclerotic lesions and dangerous, unstable atherosclerotic plaques (pages 1059–1066).