For instance, in ischemic stroke models, stem cell-derived functional mitochondria transfer to neurons significantly elevates intracellular ATP levels, and enhances activities of respiratory enzymes including citrate synthase (CS), pyruvate dehydrogenase (PDH), and α-ketoglutarate dehydrogenase (α-KGDH), while concurrently reducing ROS concentrations [124]. This evidence concerns the gene CS and ischemic stroke.