TARDBP and amyotrophic lateral sclerosis: TDP-43 is a nuclear DNA/RNA binding protein that is mutated in 4% of familial amyotrophic lateral sclerosis (ALS) (Kabashi et al., 2008; Sreedharan et al., 2008); however, its cytoplasmic accumulation is also observed in neurons of almost all patients with sporadic ALS and defines the major pathological subtype of frontotemporal lobar degeneration (FTLD) (Neumann et al., 2006).