Genome-wide association studies (GWASs) have identified numerous genetic variants associated with sporadic AD, such as GRB2-associated binding protein (GAB2), galanin-like peptide (GALP), piggyBac transposable element derived 1 (PGBD1), tyrosine kinase, non-receptor 1 (TNK1) and clusterin (CLU, also known as apolipoprotein J) [55]. This evidence concerns the gene PGBD1 and Alzheimer disease.