FOLR1 and ovarian cancer: Furthermore, the importance of the functionalization with folic acid was demonstrated by the fact that non-formulated nanoparticles demonstrated phototoxic effect for both cell lines upon illumination at 480 nm (8.7 J/cm2) or 540 nm (9.5 J/cm2), while functionalized MSN were only phototoxic for FRα overexpressing ovarian cancer cell lines [27].