In addition, deficient PDGFRβ signaling in AD also can lead to pericyte loss causing BBB disruption independently of Aβ.505 In vitro cultured pericytes were suggested to rapidly clear extracellular Aβ40 via LRP1, while excessive accumulation of Aβ in pericytes over longer periods of time resulted in cell death.506 Pericytes dysfunction may also involve in the pathology of ALS. This evidence concerns the gene LRP1 and Alzheimer disease.