NOTCH3 and CADASIL: Notch3 mutations underlie CADASIL, a cerebral arteriopathy characterized by cerebrovascular dysfunction, stroke and premature vascular dementia.5 Notch3 mutations cause CADASIL, likely through gain-of-function (GOF) effects over a loss-of-function mechanism.6 The TgNotch3R169C mouse, a transgenic model of GOF Notch3 mutation has been used to study the pathophysiology of Notch3 in CADASIL and other conditions.7,8 Here, we studied this model in PH.