TREM2 and Alzheimer disease: Among them, the p.H157Y variant of Triggering Receptor Expressed on Myeloid Cells 2 (TREM2) was identified from a relatively small number of carriers and conferred an increased AD risk with an odds ratio (OR) of 11.01 (minor allele frequency (MAF), 0.4%) in a Han Chinese cohort [5], whereas in a Caucasian cohort used in the Alzheimer’s Disease Sequencing Project, the OR was 4.7 (MAF, 0.06%) [6].