These kinds of mutations were found to impair the binding ability of TREM2 to a group of its ligands, glycosaminoglycans.192 The AD associated TREM2 mutations seem to reshape the epitopes on the surface of TREM2, and reduce its binding with some ligands, thus remodel the response of TREM2 expression immune cells to the stimulus in the microenvironment. The gene discussed is TREM2; the disease is Alzheimer disease.