Changes in cerebral blood flow as measured by ASL MRI are significantly correlated with the presence of Aβ, and DCE MRI studies demonstrate that BBB breakdown precedes accumulation of Aβ and tau and possibly acts independently of AD pathology (Yan et al., 2017; Nation et al., 2019; Montagne et al., 2020; Gold et al., 2021; Uchida et al., 2022). The gene discussed is MAPT; the disease is Alzheimer disease.