APOE and Alzheimer disease: AFM studies further illustrate that the alteration of bilayer mechanical properties induced by lipid composition impact the ability of Aβ to bind membranes, by demonstrating that astrocyte secreted lipoprotein particles containing different isoforms of apolipoprotein E (apoE), of which the apoE4 allele is a major risk factor for the development of AD, protect TBLE bilayers from Aβ(1–40) induced disruption (Legleiter et al., 2011).