TNF and myeloid sarcoma: We propose that pro-inflammatory cytokines, such as TNF, can diffuse into the hippocampal grey matter from the CSF or be induced in glial cells by dying neurons/Aβ plaques/reactive microglia, to induce necroptosis and neurodegeneration via TNFR1 signaling, similar to our findings in MS cortical grey matter [6, 34, 46].