Examining each gene in the p53 pathway according to its p53 weighting in PROGENy revealed that the genes with the strongest responsiveness in p53 activity in ALS iPSMNs included CDKN1A, SESN1, RRM2B, MDM2, C2orf66, ZNF561 and ZMAT3 (Fig. 2e). The gene discussed is MDM2; the disease is amyotrophic lateral sclerosis.