The protein STAT3 helps the immune system to recognise leukemic cells. This interaction, which is important for future immunotherapies, is now understood in detail thanks to a study at the Karl Landsteiner University of Health Sciences (KL Krems). The study showed that STAT3 influences the formation of surface structures on leukemic cells that make them vulnerable to the immune system. If these structures are missing, leukemic cells can escape the body's innate immune surveillance. The expression of STAT3 in and the surface structures on leukemic cells could be a potential biomarker for future immunotherapies.