C9orf72 and frontotemporal dementia: To measure C9orf72 protein levels, we performed quantitative Western blot analysis from control and C9orf72 ALS/FTD iPSC-MG lysates, which revealed a significant reduction of C9orf72 protein in C9orf72 ALS/FTD iPSC-MGs and was rescued in an isogenic control line (Figures 3C, D).