Since PDGFRβ is expressed by both pericytes and vSMCs [38, 71, 79], and its signaling pathway is crucial for regulating pericyte recruitment [10, 17], our results of PDGFRβ loss in postmortem retina from MCI patients suggest an early compromised vascular integrity during the AD continuum, similar to that found in the brain [11, 24, 81]. Here, PDGFRB is linked to Alzheimer disease.