TREM2 and Nasu-Hakola disease: Interestingly, Grp17 has been previously associated with Nasu-Hakola disease (Satoh et al., 2017), a disease characterized by homozygous loss of function of Trem2 or its signaling partner Tyrobp (Paloneva et al., 2002), and has been successfully targeted with a marketed antiasthmatic drug that reduces neuroinflammation and elevates hippocampal neurogenesis resulting in improvements to learning and memory in older animals (Marschallinger et al., 2015).