Olah et al[44] used human brain autopsies and RNA-Seq to conduct a comprehensive transcription landscape assessment of the aged human microglia, and found that some susceptibility genes associated with late-onset AD, such as triggering receptor expressed on myeloid cells-2 (TREM2), inositol polyphosphate-5-phosphatase D (INPP5D), membrane spanning 4-domains A4A (MS4A4A), sortilin related receptor 1 (SORL1), and myeloid cell surface antigen 33 (CD33), were involved during the aging. Here, TREM2 is linked to Alzheimer disease.