A hexamer repeat expansion (GGGGCC) located in the 5′ regulatory region of the C9ORF72 gene, causing hereditary amyotrophic lateral sclerosis, has been shown to reduce the ability of the surrounding region to promote the expression of a reporter protein in human kidney and neuroblastoma cell lines40. The gene discussed is C9orf72; the disease is familial amyotrophic lateral sclerosis.