CYCS and breast carcinoma: In the view of the results presented so far it is important to answer if other members of the retinoid family have also such a spectacular effect on the redox status of cytochrome c. Figure 4 shows Raman spectra of mitochondria for breast cancer cells SK-BR-3 (control) and SK-BR-3 incubated with retinoic acid, retinol and retinyl palmitate.