TREM2 and Parkinson disease: Mapt, the gene encoding for the tau protein associated with different types of neurodegenerative disorders (Spillantini and Goedert, 2013), Pink1, a gene that can cause PD when mutated, and Sqtsm1, a gene involved in sporadic amyotrophic lateral sclerosis pathology (Fecto, 2011), are all part of this module suggesting that all these neurodegenerative pathologies may share an underlying molecular mechanism in which Trem2 plays a central role.