MAPT and Alzheimer disease: Therefore, based on the similarities described between the visual system and the Central Nervous System (CNS) both in human and rodent experimental models of AD neurodegeneration, we investigated whether: (i) tau cleavage—in particular at its N-terminal extremity—could be detected in eyes of symptomatic Tg2576 mice, as we previously found in the hippocampus; (ii) the systemic delivery of 12A12mAb targeting the pathogenic 20–22 kDa NH2htau fragment could represent a valuable therapeutic opportunity to ameliorate the retinal injury, known to be associated with their phenotype [1, 6, 9, 72].