Fibroblasts from ALS patients carrying C9orf72 mutations and healthy age–matched controls (Table 2), previously reported and successfully differentiated (42), were reprogrammed into induced neural progenitor cells (iNPCs), then differentiated into induced neurons (iNeurons), as assessed by the expression of neuronal markers βIII-tubulin, MAP2, and NeuN (Fig S3A and B). The gene discussed is RBFOX3; the disease is amyotrophic lateral sclerosis.