Accumulation of 3‐OH fatty acid species was also detected in a mouse model of Ndufs4 deficiency (Leong et al, 2012) and in isolated mitochondria treated with respiratory chain inhibitors (Jin et al, 1992), suggesting that this metabolic signature attributable to NAD+/NADH redox imbalance can be shared by genetically diverse forms of mitochondrial myopathy. This evidence concerns the gene NDUFS4 and Mitochondrial myopathy.