TGFB1 and aortic aneurysm: Additionally, the ablation of TGF-β signaling in VSMCs by the genetic inactivation of Tgfbr2 postnatally results in aortopathy and dissections as well as an exacerbation of pathology in mice with a pre-existing genetic predisposition to aortic aneurysm, suggesting that postnatal aortic VSMCs require a basal level of TGF-β signaling for homeostasis [317,318,408].