The down regulation of ATP5B we have identified in differentiated motor neurons from sporadic ALS patients in the present microarray analysis correlates with previous findings of reduced cytochrome oxidase and ATP synthase activities described in neurodegenerative disorders (Schägger and Ohm, 1995; Bosetti et al., 2002; Sergeant et al., 2003; Basso et al., 2004; Pamplona et al., 2005). The gene discussed is ATP5F1B; the disease is amyotrophic lateral sclerosis.