Taken together, these data, obtained from both Tau KO (Fig. 3, Fig. 4) and IL-6 KO (Fig. 5, Fig. 6) mice, indicated that IL-6 elevation in hippocampi of young mice was dependent on Tau, but independent of mitochondrial dysfunction, synaptic loss and cognitive impairment in young mice. The gene discussed is IL6; the disease is Cognitive impairment.