Due to this, the relationship between microglia and the speed of Tau activity might be involved in a vicious cycle described as the following: first, Tau is transferred from the neurons to the microglia, thereby activating it to produce neurotoxic inflammatory molecules and cytokines, such as IL-1β and tumor necrosis factor-α (TNF-α); afterward, Tau can be phagocytized and secreted extracellularly, consequently increasing the progressive spread of tauopathy. Here, MAPT is linked to tauopathy.