This correlates with higher expression of key enzymes of the glycolytic pathway (Ldh, Pfk, Hex-A, PyK), together with a dramatic increase in total body lactate in larvae lacking physiological levels of Bcs1.These are typical markers of BCS1L-linked CIII deficiency and, more generally, of mitochondrial disease. Here, BCS1L is linked to inborn mitochondrial metabolism disorder.