Pericyte loss has been demonstrated using electron microscopy of AD cortex (Farkas and Luiten, 2001; Baloyannis and Baloyannis, 2012) and by decreased levels of pericyte marker platelet derived growth factor receptor β (PDGFRβ) in the precuneus and underlying white matter (Miners et al., 2018). This evidence concerns the gene PDGFRB and Alzheimer disease.