TREM2 and brain ischemia: In addition, previous experimental studies suggested a neuroprotective role of TREM2 activation or up-regulation after cerebral ischemia/reperfusion injury [4, 13–15], while sTREM2 might inhibit the beneficial function of TREM2 through acting as a decoy receptor and competitively binding the ligands of TREM2 [7, 34].