From the clinical perspective, GFAP concentrations have been correlated negatively with cognitive performance, brain volumes, and functional independence and positively with rates of cognitive decline and temporal atrophy in those with FTD (AD as well) and presymptomatic GRN and C9orf72 mutation carriers [54,125,126,127,130,133]. The gene discussed is C9orf72; the disease is Alzheimer disease.