Representative Verhoeff-Van Gieson stains along the circumferential direction for the (A) MFS Young, (B) MFS Old, (C) TAA, (D) HH Young, (E) HH, and (F) porcine groups. Elastic fibers are shown in black, collagen in red, and other tissue elements as yellow/brown. MFS Old, Marfan syndrome with thoracic aortic aneurysm >40 years; MFS Young, Marfan syndrome with thoracic aortic aneurysm <40 years; TAA, non-Marfan thoracic aortic aneurysm; Healthy human (HH), human thoracic aortic tissue without known cardiovascular disease; Healthy human young (HH Young), human thoracic aortic tissue ~54 years without known cardiovascular disease; Porcine, porcine thoracic aortic tissue without known cardiovascular disease.