Although defective signaling in a number of different pathways could influence the EndMT/EMT during OFT development, the familial inheritance of BAV with a NOTCH1 mutation, the lack of strong evidence for BAV association with TGFβ mutations, and the results described here, collectively imply that a parallel deregulation of the NOTCH/VEGF pathways, rather than a TGFβ-driven process, may be more relevant for the development of aneurysm in BAV, in line with our recently published observations42. The gene discussed is NOTCH1; the disease is aneurysm.