PEPD and Alzheimer disease: TREM2 signaling is in part mediated through a MG membrane-associated tyrosine kinase-binding protein/DNAX activation adaptor protein of 12 kDa (TYROBP/DAP12), however, no deficit in TYROBP/DAP12 in AD or PrD has yet been identified, and we cannot exclude deficiencies in other phagocytic proteins at the present time (Yaghmoor et al., 2014; Zhu et al., 2015).