Synaptic loss, the main feature associated with cognitive decline in AD, correlates better with tau neurofibrillary tangles, the other neuropathological hallmark of the disease (Savva et al., 2009; Seemiller et al., 2021; Stopschinski et al., 2021), and Aβ deposits are sometimes also seen in cognitively healthy subjects (Lue et al., 1999; Näslund et al., 2000). This evidence concerns the gene MAPT and Alzheimer disease.