TGFB1 and Alzheimer disease: In addition to increased levels of TNF-α, increased levels of the inflammatory cytokines IL-1β, TGF-β, IL-12, and IL-18 in the CNS are also correlated with AD progression and increase damage in the brains of AD patients.240 Interestingly, CD22 is a B-cell receptor that functions as a negative regulator of phagocytosis.