Alois Alzheimer identified first abnormal deformation in the brain of diseased people with mental disorder. The disorder is clinically characterized by a progression from episodic memory problems to a slow global decline of cognitive function, ending with the final stage when patients become bedridden and death occurs on average 9 years after diagnosis. The current standard of care does not cover the approved and effective treatment of both cognitive and non-cognitive symptoms. Tremendous effort was put in investigation of the disease development. The uncovered molecular mechanism shed light on aspartic proteases, the smallest protease class with about 15 members in the human genome. Here we summarise the most important structure-based developments on one of the most popular aspartic protease target BACE1.