APOE and early-onset autosomal dominant Alzheimer disease: This in vivo “lipid sink” role has been mimicked in transwell co-cultures, where ectopic LDs in hippocampal neurons from ApoE3 or ApoE4 humanized mouse models of Alzheimer’s disease are cleared by astrocytes via ApoE-dependent extracellular lipid transport (Qi et al., 2021).