TREM2 and Alzheimer disease: Whole-exome sequencing studies have identified robust AD associations with rare missense variants in TREM2, AKAP9, UNC5C, ZNF655, IGHG3, CASP7 and NOTCH3 [4,5,6,7,8,9], and it is expected that more AD-related rare variants will be identified by whole-genome sequencing (WGS) studies, because some rare variants, including those in non-coding regions, likely contribute to AD risk.