C9orf72 and frontotemporal dementia: Regarding C9orf72-ALS/FTD, a recent study has associated the mutation to altered astrocytic extracellular vesicle secretion of micro RNAs (miRNAs) that are involved in the regulation of axonal maintenance genes and restoration of miRNA activity could partially ameliorate toxicity of conditioned media from C9orf72 patient derived astrocytes or motor neurons (Varcianna et al., 2019).