VCP and sarcoma: In addition, much of the animal-model research focuses on mutations in the TARDBP transactive response DNA-binding protein gene (TDP-43) associated with approximately 5% of fALS cases [53], sarcoma fusion protein (fused in sarcoma (FUS)) and valosin-containing protein (VCP), due to its link to fALS and diseases of a similar nature [52,54].