As expected for advanced atherosclerosis, a necrotic core formed, and it was markedly reduced in Mif-2-deficient mice (Fig. 4f), whereas plaque collagen content (Supplementary Fig. 8a, b), fibrous cap thickness (Supplementary Fig. 8c, d), and smooth muscle cell counts as read out by α-smooth muscle actin (SMA)-positive lesion area (Supplementary Fig. 9a, b) remained unaffected. This evidence concerns the gene SMN1 and atherosclerosis.