The spliceosome is the molecular machine in our cells that puts the blueprints for proteins into a readable form. Researchers at the Max Planck Institute (MPI) for Multidisciplinary Sciences in Göttingen (Germany) and the Institute for Cancer Research (ICR) in London (UK) have now uncovered the crucial step that switches on the spliceosome. As they have shown, this macromolecular machine is activated by two molecular motors. The findings from the study could provide new approaches to improve potential cancer drugs that target the splicing process.