APP and Alzheimer disease: Indeed, a bioinformatics search among the highly abundant axonally localized or translated mRNAs identifies a number of genes associated with various neurological disorders (Fig. 2), including amyloid β precursor protein (APP) and ubiquitin carboxyl-terminal hydrolase L1 (UCHL1) related to Alzheimer’s disease (AD) and Parkinson’s disease (PD) susceptibility [9,39,43].