MAPT and Down syndrome: A causative role of Aβ in AD pathogenesis is supported by strong evidences, including genetic of FAD (De Jonghe, 2001; Selkoe, 2001; Chen et al., 2014) and Down’s syndrome (Lejeune et al., 1959; Head et al., 2012), toxicity of Aβ aggregates (Selkoe et al., 2016), Aβ activation of neuron inflammation (Eng et al., 2004) and Aβ potentiation of tau pathology (Jin et al., 2011).