Thus, five mutant genes linked to familial ALS/FTD have now been shown to target the ER‐mitochondria axis and were studied (TARDBP, FUS and C9orf72); this may involve activation of GSK3β and breaking of the VAPB‐PTPIP51 tethers (Figure 7). This evidence concerns the gene C9orf72 and frontotemporal dementia.