Itis worth noticing that a similar effect of downregulation ofcytochrome c concentration was reported for braincancer cells vs cancer aggressiveness.6 We showed that the Raman signal of the band at 1584 cm–1 related to the concentration of cytochrome c inmitochondria of a single cell in vitro decreaseswith brain tumor aggressiveness.6,9. The gene discussed is CYCS; the disease is cancer.