By contrast, dysfunction of microglia-related proteins, such as CSF1R, DAP12 and TREM2, USP18, and IRF8, is associated with secondary microgliopathy in a diverse set of neurological diseases, including Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), Parkinson’s disease (PD) and frontal temporal dementia (FTD) diseases [6–9]. Here, TREM2 is linked to Alzheimer disease.