APOE and Alzheimer disease: Cx/Panx HCs are also expressed by astrocytes and are likely involved in the release of critical toxic amounts of soluble factors-such as glutamate, adenosine triphosphate (ATP), complement component 3 derivate C3a, tumor necrosis factor (TNFα), apoliprotein E (ApoE), and certain miRNAs-known to play a role in the pathogenesis of AD, ALS, and other neurodegenerative disorders.