Many different mechanisms have been suggested to explain the development of a MDR phenotype in cancer cells, one of the extensively studied form of these mechanisms is overexpression of several energy dependent drug efflux pumps that belong to the ATP-binding cassette family of transporters, such as the P-glycoprotein (P-gp) and the MDR-associated proteins (MRPs) [33]. This evidence concerns the gene MRPS7 and cancer.