Every year, some 13,000 people in Germany are diagnosed with leukemia. Despite intensive chemotherapy, around one in two of them die. Therapies currently available have severe side effects and inhibit the formation of new healthy blood cells in particular. One alternative is therapy concepts that harness the immune system’s natural power. It is important to note, however, that tumor cells have mechanisms capable of slowing down the immune cells’ attack. Professor Evelyn Ullrich’s team at Universitaetsmedizin Frankfurt has now succeeded in making leukemia-specific immune cells less sensitive to the influence of tumor cells, thereby significantly increasing their effectiveness.