The instant mark represents mechanism of action of a texaphyrin molecule as it interacts with a cancer cell. The ovals in the foreground, at the bottom, left side represent cancer cells. One texaphyrin molecule, depicted by a small pentagon with a "X" in the middle, can be seen in the foreground inside one of these cells. The main set of images, in the middle of the picture, shows a close-up of one of the cancer cells with a texaphyrin molecule in it. The zigzag line represents an intra-cellular reducing metabolite like ascorbate, etc. The little "ball" attached to the zigzag line represents an electron. The texaphyrin gets activated by interacting with radiation, depicted by the beam of light on the plus sign in the texaphyrin, and then strips the electron from the reducing metabolite and transfers it to the right side of the texaphyrin. The electron then interacts with a passing oxygen molecule, depicted on the right side of the picture as a round sphere. When oxygen accepts the electron that has been passed to it by the texaphyrin molecule, it changes into a hydrogen peroxide molecule, which is shown on the right side of the picture as a "fluffy" sphere. The large sphere in the top, right of the picture represents the cell's nucleus. It is included to show that the texaphyrin molecule and the described process take place outside of the cell's nucleus.