Clinical relevance of drug resistance genes in malignant disease.

Drug resistance is a major reason for the failure of anticancer chemotherapy. Multidrug resistance has been recognized as an important type of resistance and can be due to various mechanisms. Here we review the published data on the presence and clinical significance of these mechanisms in solid tumors and hematological malignancies. We also refer to new treatment strategies resulting from the knowledge of the various mechanisms of drug resistance present in malignant diseases.