Quantification of C9orf72 expression levels in Alzheimer's disease and non-Alzheimer's disease brains. Expression of chromosome 9 open reading frame 72 (C9orf72) protein studied in the frozen frontal cortex tissues of seven Alzheimer's disease (AD) and 14 non-AD cases by western blot analysis as shown in Figure 3. Signal intensity of all immunopositive bands combined was quantified using ImageJ software, and was standardized individually by the signal intensity of Hsp60. Signal intensity ratio: (a) sc-138763/Hsp60, (b) HPA023873/Hsp60, and (c) glial fibrillary acidic protein (GFAP)/Hsp60. (d) Correlation between the GFAP/Hsp60 and HPA023873/Hsp60 ratios in individual cases.