EIF2D and frontotemporal dementia: Furthermore, the nuclear E3 ubiquitin ligase linker protein SPOP and the eukaryotic translation initiation factor 2D (eIF-2D/eIF2D) can inhibit the protein toxicity of PR50 (Pro Arg 50, a dipeptide repeat protein (DPR)), indicating that they are therapeutic targets for C9orf72-related ALS/FTD [155,156].