The same activation was, however, seen in human iPSC-derived neurons harboring not only the C9orf72 hexanucleotide expansion but also further different familial ALS-causing mutations in genes like TARDBP/TDP43, profilin 1 (PFN1), FUS, kinesin family member 5A (KIF5A), and NIMA related kinase 1 (NEK1), and it was associated with DNA damage [107]: a pathway that is indeed increasingly implicated in ALS but also in FTD [110]. Here, C9orf72 is linked to frontotemporal dementia.