TARDBP and amyotrophic lateral sclerosis: TDP-43 is known to bind to at least 6,000 mRNAs in the murine brain and to modify the expression level of at least 600 mRNAs (Polymenidou et al., 2011), and as such it was hypothesized that mutant TDP-43 may induce differentially expressed genes and isoforms, which may be part of the pathogenicity of ALS.