In the present study we show that the expression of the transcription co-factor proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and downstream mitochondrial antioxidant enzymes peroxiredoxin-3 (Prx3) and thioredoxin-2 (Trx2) is markedly increased in astrocytes in active multiple sclerosis (MS) lesions. The gene discussed is PRDX3; the disease is myeloid sarcoma.