While it cannot be ruled out that amyloid-β and tau pathology arise as a result of shared or independent upstream mechanisms (e.g., age or genetic related abnormalities in amyloid-β turnover/clearance [217, 218], or cardiac and metabolic conditions [219]), the evidence so far lends support to the modified amyloid-β cascade pathway, whereby amyloidosis precedes the spread of pathologic tau, which in turn causes neurodegeneration and cognitive decline [154, 172]. This evidence concerns the gene MAPT and amyloidosis.