The existence of mutations in genes encoding cytoskeletal proteins or the cellular transport machinery highlights the involvement of these processes in ALS/FTD. These include tubulin α4A (Smith et al., 2014a; Perrone et al., 2017), a major component of microtubules, neurofilament heavy chain (Figlewicz et al., 1994), a type of intermediate filament, and profilin-1 (Wu et al., 2012; Dillen et al., 2013; Smith et al., 2014b), which is involved in actin polymerization. Similarly, dynactin-1, involved in axonal transport (Puls et al., 2003; Münch et al., 2004; Münch et al., 2005; Liu et al., 2017) and SCFD1 (Sec1 family domain containing 1), involved in ER to Golgi transport (van Rheenen et al., 2016), are also mutated in a small proportion of patients, further implying that protein transport is impaired in ALS/FTD.