TNF and Alzheimer disease: In accordance with this notion, MSC transplantation into AD model mice suppressed the release of proinflammatory cytokines, such as TNF-α, IL-1β, and IL-6, from activated microglia and astrocytes [44, 59] and shifted microglial polarization from the proinflammatory M1 phenotype to the immunomodulatory M2 phenotype [33] (Figure 16).