Indeed, in Apoe–/– mice with established Western diet–induced atherosclerosis, Pdgfrb deletion with Myh11-CreERT2 reduces fibrous cap SMA+ cells that are marked by the Myh11-CreERT2 lineage by 50%, without altering the total number of SMA+ cells in the fibrous cap (53). Here, APOE is linked to atherosclerosis.