APOE and Alzheimer disease: Genetic mutations in APOE (apolipoprotein E) [5], MAPT (tau) [6], TREM2 (triggering receptor expressed on myeloid cells) [7,8], MS4A4(membrane-spanning 4-domains A4) [9,10], CD33 [9,10], ABCA7(ATP binding cassette subfamily 7) [9], and CLU (clusterin) [11] have been linked to AD via genome-wide association studies (GWAS) or by pathological examination (AlzForum).