Although oligomeric Aβ can induce sTREM2 shedding and viral infections such as HIV increased levels of sTREM2 in the CSF, conditions that modulate sTREM2 shedding from full-length TREM2 are not fully understood [102, 105] and may occur to block the activity of full-length TREM2 and its downstream signaling. Here, TREM2 is linked to viral infectious disease.