APOE and atherosclerosis: To determine the role of macrophage iron accumulation in the development of atherosclerosis, we crossed Fpn1LysM/LysM mice [21] with Apoe−/− mice to generate Apoe−/−Fpn1LysM/LysM mice, in which Fpn1 was specifically deleted in macrophages on the genetic background of global Apoe knockout.