TGFBR1 and aortic aneurysm: Despite the evidence for a potential role for ALK5 in the endothelium (Sridurongrit et al., 2008), most studies in OFT and aortic pathologies, such as aortic aneurysms, have been focused on the role of TGF-β signaling in SMCs and not ECs (Choudhary et al., 2009; Guo and Chen, 2012; Gillis et al., 2013; Yang et al., 2016; Takeda et al., 2018).