There is a known vulnerability of motor cortex in this disease which may cause either FTD or ALS.28 Using fluorine 18-labeled fluorodeoxyglucose positron emission tomographic imaging, hypermetabolism was observed in this region in the majority of asymptomatic C9orf72 expansion carriers compared to controls,29 possibly reflecting neuroinflammation. The gene discussed is C9orf72; the disease is amyotrophic lateral sclerosis.