Seeing is believing

Now, drugs releasing within a treated cancer cell could be visualized via fluorescence resonance nnergy transfer (FRET) imaging. Therapies specifically targeting to pathological cells should be believed.

This image depicts drug release within a treated cancer cell. Once inside the cell, the drug turns from red to green as receptor endocytosis releases it from its folate-linker. By linking to the vitamin, toxic drugs are transported directly to the cancer cell and do not harm healthy cells. [the origin]