The present invention is a biomarker of chemotherapeutic drug-resistant cancer stem cells and a method of inhibiting the growth of drug-resistant cancer stem cells. In one embodiment the cancer stem cells are testicular cancer germ cells. In another embodiment the present invention is a method of overcoming drug resistance in cancer treatment where the combination of low dose decitabine and administration of a chemotherapeutic drug to which cancer cells were resistant results in successful cancer treatment.
