RAB1B and early-onset autosomal dominant Alzheimer disease: In contrast, only Rab1A, and not Rab1B, has been associated with neurological disorders, for example, Parkinson’s disease (Winslow et al, 2010; Coune et al, 2011; Ejlerskov et al, 2013; Mazzulli et al, 2016; Hatstat et al, 2022), Alzheimer’s disease (Mohamed et al, 2017), amyotrophic lateral sclerosis (Webster et al, 2018), and intellectual disability (Tabata et al, 2022).