Transactivation response (TAR) DNA-binding protein of 43 kDa (also known as TARDBP or TDP-43) was first isolated as a transcriptional inactivator binding to the TAR DNA element of the HIV-1 virus. Neumann et al. (2006) found that a hyperphosphorylated, ubiquitinated, and cleaved form of TARDBP, known as pathologic TDP-43, is the major component of the tau-negative and ubiquitin-positive inclusions that characterize amyotrophic lateral sclerosis (ALS) and the most common pathological subtype of frontotemporal lobar degeneration (FTLD-U).10782-2-AP is a rabbit polyclonal antibody recognizing the cleavage product of 20-30 kDa in addition to the native and phosphorylated forms of TDP-43. Immunohistochemical analyses of TDP-43 using this antibody detect both normal diffuse nuclear staining and insoluble inclusions in pathologic tissues. A variety of TDP-43-positive pathological inclusions have been found in FTLD-U (now referred to as FTLD-TDP), including neuronal cytoplasmic inclusions (NCIs), dystrophic neurites (DNs), neuronal intra-nuclear inclusions (NIIs), and glial cytoplasmic inclusions (GCIs).