PTBP1 and frontotemporal dementia: TDP-43 [TAR DNA-binding protein] is a 43 kDa RNA binding protein identified as the main component of ubiquitinated protein aggregates (Tsuda et al., 2008; Murakami et al., 2012; Vaccaro et al., 2012a,b; Han et al., 2013; Therrien et al., 2013) found in patients with sporadic ALS (Neumann et al., 2006) and also in some cases of FTD (see Section “Frontotemporal Dementia”).