Compelling clinical and neuropathological evidence has demonstrated that a global deficit in acquisition and integration of visual information crucially contributes to impairment of episodic memory in AD [18,124,125,126,127,128,129,130] and mild cognitive impairment (MCI) subjects [131,132], in association with a high burden of tau and β-amyloid in their visual system [83,84,85,133,134,135]. The gene discussed is MAPT; the disease is Alzheimer disease.