In addition, recent whole genome and whole exome analyses have identified rare coding variants in TREM2 [5, 6], PLD3 [7], ABCA7 [8, 9], and SORL1 [10, 11] that are associated with AD and confer risk comparable to that of carrying one APOE ε4 allele. This evidence concerns the gene TREM2 and Alzheimer disease.