C9orf72 and amyotrophic lateral sclerosis: Based on the above findings, we explored the relationship between the genotype and phenotype of ALS disease and discovered that nucleocytoplasmic transport defects were detected in hiPSCs-MNs of C9orf72 and TDP43 mutant patients, but not in SOD1 ones, indicating that different genotypes may cause MNs degeneration through different mechanisms.