Editing Reelin (section)

===Alzheimer's disease===
The Reelin receptors [[ApoER2]] and [[VLDLR]] belong to the [[LDL]] receptor gene family.<ref name="pmid11252768" /> All members of this family are receptors for [[Apolipoprotein E]] (ApoE). Therefore, they are often synonymously referred to as 'ApoE receptors'. ApoE occurs in 3 common isoforms (E2, E3, E4) in the human population. [[ApoE4]] is the primary genetic risk factor for late-onset [[Alzheimer's disease]]. This strong genetic association has led to the proposal that ApoE receptors play a central role in the pathogenesis of Alzheimer's disease.<ref name="pmid11252768" /><ref name="pmid17053810" /> According to one study, reelin expression and [[glycosylation]] patterns are altered in [[Alzheimer's disease]]. In the cortex of the patients, reelin levels were 40% higher compared with controls, but the cerebellar levels of the protein remain normal in the same patients.<ref name="alz" /> This finding is in agreement with an earlier study showing the presence of Reelin associated with amyloid plaques in a transgenic AD mouse model.<ref name="alzmouse" /> A large genetic study of 2008 showed that RELN gene variation is associated with an increased risk of Alzheimer's disease in women.<ref name="pmid18599960" /> The number of reelin-producing Cajal-Retzius cells is significantly decreased in the first cortical layer of patients.<ref name="pmid16051543" /><ref name="pmid17453452" /> Reelin has been shown to interact with [[amyloid precursor protein]],<ref name="pmid19515914" /> and, according to one in-vitro study, is able to counteract the Aβ-induced dampening of [[NMDA-receptor]] activity.<ref name="Herz2009relnabeta" /> This is modulated by ApoE isoforms, which selectively alter the recycling of ApoER2 as well as AMPA and NMDA receptors.<ref name="pmid20547867" />