Every neurodegenerative disease displays a characteristic regional distribution of lesions along the central nervous system that results from a twofold process: selective spread of the pathologic protein (Aβ, tau, α-synuclein, TDP-43, PrPSc, among others) along specific connectivity circuits, and selective vulnerability of certain neuron populations to its toxic properties [8]. This evidence concerns the gene MAPT and neurodegenerative disease.