This is a simplified presentation of the CML/cancer targeting by the drug Gleevec™. There are many more details than could be presented here. It is represents as a model of finding a drug for each type of cancer, rather than the one, single “magic bullet” that kills all cancers. Remember, there are always complexities in this type of research to treatment process, such as patient genetic and environmental variation that leads to differences in drug metabolism, uptake, and binding. Also, changes in drug dose, mutation of the bcr-abl gene, and other events can affect the effectiveness of the treatment and the relapse rate. Biological systems are extremely complex and difficult to modulate in the specific, targeted manner necessary to treat cancer ideally.