Multidrug resistance is the main problem in anticancer therapy. Cancer cells use many defense strategies in order to survive chemotherapy. Among known multidrug resistance mechanisms the most important are: drug detoxification inside the cell using II phase detoxifying enzymes and active transport of the drug to the extracellular environment. Cancer cells may be also less sensitive to proapoptotic signals and have different intracellular drug distribution, which makes them more resistant to anticancer drugs.