Moreover, it has been shown that Vps35/retromer regulates the recycling of the microglial receptor TREM2 (triggering receptor expressed on myeloid cells 2), and TREM2 rare variants were found to strongly increase the risk of developing AD, most likely by regulating microglial function, such as proinflammatory responses and phagocytosis [23,24,25]. Here, TREM2 is linked to Alzheimer disease.