Among these, factors closely related to brain macrophages, such as TREM2 or APOE-positive macrophages, have been highlighted.848,849 These macrophage-related risk factors underscore the critical role of brain-associated macrophages/microglia in the pathogenesis of neurodegenerative diseases.850 This is particularly evident in Alzheimer’s Disease (AD) and Parkinson’s Disease (PD), the two most common neurodegenerative disorders. This evidence concerns the gene TREM2 and Parkinson disease.