Multiple studies have shown that the cell-surface proteins heparan sulfate proteoglycan (HSPG) and low-density lipoprotein receptor-related protein 1 (LRP1) mediate uptake and degradation of Tau and α-syn associated with Alzheimer’s disease and PD (68, , , , –73). Here, LRP1 is linked to early-onset autosomal dominant Alzheimer disease.