HLA-DRB1 and Alzheimer disease: In addition to APOE, IGAP 2013 identified 19 AD susceptibility loci, including 11 novel loci (SORL1, FERMT2, SLC24A4/RIN3, PTK2B, ZCWPW1, HLA-DRB5–HLA-DRB1, MEF2C, INPP5D, CELF1, NME8 and CASS4) and 8 known loci (MS4A6A, CR1, CD2AP, CD33, PICALM, EPHA1, CLU, ABCA7 and BIN1) [4].