Of interest, triggering receptor expressed on myeloid cells 2 (TREM2) is a major risk gene for neurodegeneration and AD that plays a key role in changing microglial activity from its homeostatic state to one that is disease-associated (Jay et al., 2017; Krasemann et al., 2017), indicating a potential for variations in microglial reactivity to moderate effects of inflammatory markers on cognition during this stage. The gene discussed is TREM2; the disease is Alzheimer disease.