TREM2 and neurodegenerative disease: While murine models of neurodegenerative disease indicate that loss or dysfunction of TREM2 signaling impacts upon microglial function and disease progression (Ulrich et al., 2014, Yuan et al., 2016), the precise role of TREM2 in microglial biology and the consequences of its dysregulation in neurodegenerative disease pathogenesis remain to be determined.