The remaining FTD cases are categorized as FTD-Tau, and less commonly FTD-FUS (fused in sarcoma) and FTD-UPS (ubiquitin-proteasome system) (Holm et al., 2009; Neumann et al., 2009; Mackenzie et al., 2010; Urwin et al., 2010). The gene discussed is HMBS; the disease is frontotemporal dementia.