UBQLN2 and frontotemporal dementia: ALS and FTD are genetically linked to protein quality control factors in the proteasome and to autophagy pathways, such as UBQLN2, p62/SQSTM1, optineurin, and VCP, as well as to RNA-binding proteins (RBPs) such as FUS, TDP-43, Ewing sarcoma protein (EWS), TAT-binding protein-associated factor 15 (TAF15), hnRNPA1, and hnRNPA2/B1 (30).