Ubiquitin frontotemporal lobar degeneration (FTLD-U) is the most common form of frontotemporal dementia (FTD) from a neuropathological point of view and shares with some variants of ALS the aggregation and deposition of TDP-43 immunoreactive intracytoplasmic inclusions in neurons. This evidence concerns the gene TARDBP and amyotrophic lateral sclerosis.