TNF and Alzheimer disease: During the last two decades much attention was paid to brain sphingolipids (SphLs) in neurodegeneration (26–28) as molecules involved in the processing and aggregation of Aβ, in the signal transduction of a cytotoxic signal induced by Aβ and of pro-inflammatory signal induced by cytokine TNFα, that are considered the main inducers of AD (29).