To date, (genome-wide) association studies identified 27 AD susceptibility loci: ABCA7, ACE2, ADAM10, ADAMTS1, APOE, BIN1, CASS4, CELF1, CLU, CR1, CD2AP, DSG2, EPHA1, FERMT2, HLA-DRB1, HLA-DRB5, INPP5D, IQCK, MAPT, MEF2C, MS4A6A–MS4A4E, NME8, PICALM, PLD3, PTK2B, SLC24H4-RIN3, SORL1, TREM2 and ZCWPW1 [20–23]. This evidence concerns the gene TREM2 and Alzheimer disease.