TGFB1 and thoracic aortic aneurysm: TGF-β signaling has been implied to protect against abdominal and thoracic aortic aneurysm formation, while systemic TGF-β inhibition enhances abdominal aortic aneurysm formation, whereas smooth muscle-cell specific TGF-β neutralization can increase the chances of aortic thoracic aneurysm development [92].