Additional rare variants in TREM2 including p.R62H, p.T96K, p.D87N, p.H157Y, p.R98W, p.T66M, p.Y38C and p.Q33X were subsequently identified to be associated with AD [3–6] In addition, recent genome-wide association studies (GWAS) including low-frequency variants identified the TREM2 locus for AD [7, 8]. Here, TREM2 is linked to Alzheimer disease.