For example, P2Y12 receptor protein expression was found to be elevated in the cortical microglia of Trem2-/- mice and in a preclinical mouse model of AD (Götzl et al., 2019; Griciuc et al., 2019), although the mechanistic link between purinergic receptor expression and TREM2 function remains poorly understood. The gene discussed is TREM2; the disease is Alzheimer disease.