In the past decade, mutations in several additional genes, including GGGGCC hexanucleotide-repeat expansion in the C9ORF72 gene (DeJesus-Hernandez et al., 2011; Renton et al., 2011; Gijselinck et al., 2012) and point mutations in UBQLN2 (Deng et al., 2011), VCP (Johnson et al., 2010), CHMP2B (Momeni et al., 2006; Parkinson et al., 2006), and TBK1 (Cirulli et al., 2015; Freischmidt et al., 2015; Pottier et al., 2015) were also identified as genetic causes for both ALS and FTD. This evidence concerns the gene TBK1 and frontotemporal dementia.