Mouse and human atherosclerotic lesions contain EIIIA-FN. (A) A cryosection of an ApoE^–/– mouse aorta after high-fat diet for 8 weeks. EIIIA-FN is associated with lesional endothelial cells and occasional foam cells (black arrowhead). The unfilled arrowhead indicates absence of EIIIA-FN in non–lesion-associated endothelium. EIIIA-FN is not detectable in the smooth muscle wall (w). (B) Aortic lesion from an ApoE^–/– mouse after high-fat diet for 16 weeks. EIIIA-FN is detected around lesional foam cells (black arrowhead). (C) Human carotid artery, indicating EIIIA-FN associated with scattered cells in the shoulder region of the lesion (black arrowhead). EIIIA-plus FN is not detectable in the fibrotic cap (cap), necrotic core (core), or the wall (w). (D) EIIIA-FN is associated with lesional macrophages and smooth muscle cells near the luminal surface (black arrowhead). L indicates vessel lumen. Original magnification, × 100.