TNF and early-onset autosomal dominant Alzheimer disease: Several cytokines modulate signalling pathways that regulate vascular tone, some increasing the production of vasodilators (NO, PGI2), and other pro-inflammatory cytokines, such as TNF-α, upregulating the expression of the potent vasoconstrictors, Ang-II and EDN1,61 which are also elevated in Alzheimer’s disease.24