Besides the involvement in neurodegenerative processes, heterozygous knockout of certain genes, such as APOE, BACE1, or Inositol polyphosphate-5-phosphatase (INPP5D), was found to be protective against AD by slowing down amyloid progression, reducing amyloid deposition, and diminishing immune-related mechanisms (Figure 6) [137,138,139,140,141,142,143,144,145,146,147,148,149,150,151,152,153,154]. This evidence concerns the gene BACE1 and Alzheimer disease.