APOE and Alzheimer disease: Moreover, neuronal-specific downregulation of LRP1 in a mouse model of AD (the APP/PS1 mouse model) crossed with mice expressing either human Apolipoprotein E3 (APOE3) or APOE4 showed that LRP1 is crucial for APOE4-mediated Aβ pathology, thus suggesting that multiple pathways cooperate to internalize extracellular aggregates of different nature [129, 130].