Three MT-CYB polymorphisms: A14793G, A15758G and A15218G, as well as the MT-CO1 G7444A, MT-CYB T15663C and G8959A (ATP6) mutations, may affect the function of mitochondria, thus potentially playing an important role in the formation of brain tumours. The gene discussed is MT-ATP6; the disease is brain neoplasm.