Cancer begins when a normal cell cannot get enough oxygen. If the level of oxygen available falls below 40%, in order to survive, the cell will begin to ferment sugar instead of burning it. This process is irreversible and results in an energy output only 1/6 as great as oxidation. The cell then lacks the energy to manufacture a proper enzyme coating around itself. The governor on cell replication is switched off, and the cell can begin to make copies of itself wildly. This ungoverned cell replication is called cancer.
When ozone is introduced into the area, it immediately attacks the unhealthy cells because they lack a proper enzyme coating. Healthy cells are untouched. If sufficient ozone is administered over time, the tumour will be dissolved.