The phenomenon of multidrug resistance is a common cause of failure of cancer chemotherapy. Tested a number of cellular mechanisms that affect the cytotoxic effects of anticancer drugs. One of the most intensively studied forms of cell resistance to therapy resistance is caused by overexpression of membrane glycoproteins. Some membrane proteins responsible for membrane transport of drugs and genes encoding them have been identified and characterized. They play an important role in reducing the intracellular levels of drugs. Their expression has been demonstrated in a number of human tumor cells and in normal tissues. It was found that many drugs inhibit the function of proteins associated with membrane transport. Several of them exhibit toxic effects. An important issue is to search for new compounds with better therapeutic index which may be used in cancer therapy.