In support of a role for impaired neurovascular-mediated signaling, pericyte position and function are altered by disease conditions such as stroke (Hall et al., 2014; Berthiaume et al., 2018a,b), diabetes (Rom et al., 2020) and Alzheimer’s disease (AD) (Sagare et al., 2013; Nortley et al., 2019; Montagne et al., 2020), as well as disturbances in the circadian clock system (Nakazato et al., 2017)—all of which are associated with neurodegeneration. The gene discussed is CLOCK; the disease is Alzheimer disease.