All in all, this has promoted the emergence of numerous other hypotheses following the “Amyloid Cascade Hypothesis”, such the tau hypothesis [37], GSK3β hypothesis [38], oxidative stress hypothesis [39] amyloid-inflammatory hypothesis [40] and, ultimately, the multifactorial hypothesis of AD [41], which calls for taking into consideration the multifactorial nature of AD and the potential benefit of developing multi-target agents or combinational drug use. The gene discussed is MAPT; the disease is Alzheimer disease.