NOTCH3 and CADASIL: This finding suggests that in addition to untimely clearance of paramagnetic hemosiderin, there are several possible causes of iron deposition in CADASIL patients, such as blood–brain barrier (BBB) destruction (Kalimo et al., 2002, Dziewulska and Lewandowska, 2012, Li et al., 2023) and NOTCH3 mutation (Montagne et al., 2015, Zhang et al., 2017), the pathophysiological mechanism contributing to iron deposition in CADASIL remains to be elucidated.