Professor Thomas Helleday at Karolinska Institute has been awarded the Erik K. Fernström Prize for younger medical researchers. Helleday is a professor at the Department of Medical Biochemistry and Biophysics and is now recognized for his discoveries of new targets for cancer therapy. Earlier this year a team of researchers, led by Professor Helleday, were able to identify a new way of treating cancer. The concept was presented in the journal Nature and is based on inhibiting a specific enzyme called MTH1, which cancer cells, unlike normal cells, require for survival. Without this enzyme, oxidized nucleotides are incorporated into DNA, resulting in lethal DNA double-strand breaks in cancer cells. He was also the first to scientifically demonstrate the concept called “synthetic lethality” for treating cancer. Helleday proved that PARP inhibitors can selectively kill certain cancer cells without damaging surrounding healthy cells, which was a major breakthrough for the clinical treatment of mutated breast and ovarian cancers. Synthetic lethality can also be used to devise strategies to attack cancer. These PARP inhibitors are now being tested clinically all over the world, and several products are subjects to approval by the U.S Food and Drug Administration. The Eric K. Fernström Foundation was established in 1978 to promote medical scientific research. The primary objective of the Foundation is to award annual monetary prizes to researchers who have made important contributions to medical science.