Data supporting diabetes-induced microglial phenotype in db/db mice include IL-1β and TNF-α upregulation in the cortex [213] and hippocampus [220] of these mice; as well as higher secretion levels of IL-1β, IL-6, TNF-α and MCP-1 by isolated forebrain mononuclear cells [223]. This evidence concerns the gene CCL2 and diabetes mellitus.