In 1995, the PSEN1 gene, which encodes the protein presenilin 1 required for γ‐secretase to produce amyloid‐beta (Aβ) from APP, was cloned for the first time and was identified as one of pathogenic genes for the EOFAD (Perez‐Tur et al., 1995). Here, APP is linked to early-onset autosomal dominant Alzheimer disease.