C9orf72 and frontotemporal dementia: In addition, C9orf72 ALS/FTD iPSC-MG were indistinguishable from healthy control iPSC-MG when performing cytochalasin-D-dependent phagocytic activity upon exposure to human healthy brain synaptoneurosomes and engulfment of amyloid beta (Aβ) (1–40)-TAMRA.