We did not find any evidence of downregulation of respiratory chain subunits in the proteome of ALS skin fibroblasts but we discovered a downregulation of glucose metabolism (glycolysis) and malate-aspartate shuttle components (GOT1, GOT2, MDH2) suggesting a reduced fueling of OXPHOS rather than a decreased biogenesis of the respiratory chain. Here, MDH2 is linked to amyotrophic lateral sclerosis.