EIF2AK3 and supranuclear palsy, progressive, 1: Intriguingly, recent studies by Schellenberg and colleagues raise the possibility that variants of EIF2AK3, which encodes PERK, may also be a genetic risk factor in neurodegenerative diseases based on the finding that a specific protein-coding haplotype of EIF2AK3 was associated with increased risk for PSP through genome-wide association and postmortem studies (Hoglinger et al. 2011; Stutzbach et al. 2013).