In another study involving human iPSCs-derived motor neurons, mutation of the FUS NLS resulted in impairment of PARP-1 dependent DDR signalling, leading to DSB formation, neurodegeneration and the formation of FUS aggregates (Naumann et al., 2018), implying that DNA damage is an early event in the pathophysiology of FUS-ALS (Naumann et al., 2018). Here, PARP1 is linked to amyotrophic lateral sclerosis.