FUS and frontotemporal dementia: Fused in sarcoma (FUS) is an RNA binding protein that normally localizes predominantly in the nucleus, however it mislocalizes and aggregates in the cytoplasm in some instances of familiar Amyotrophic lateral sclerosis (ALS) and in 10% of Frontotemporal lobar degeneration (FTLD), one of the most frequent forms of early-onset dementia [1–3].