This is aligned with results from our study that investigated cell–cell communication within the gliovascular unit amongst endothelial cells, pericytes and astrocytes, where we found AD-related transcriptional changes in astrocytic ligands predicted to bind targets on pericytes and that the top prioritized molecular pair, pericytic SMAD3 and astrocytic VEGFA, influences pericyte functioning as it pertains to BBB regulation [33]. This evidence concerns the gene SMAD3 and Alzheimer disease.