Researchers from the University of Cologne and Heinrich Heine University Düsseldorf have identified a new form of the protein ubiquitin, which is responsible for proteostasis, i.e. protein balance, and healthy aging. The study shows that ubiquitin, which is extended at the end (CxUb), contributes to the stress resistance of cells. This discovery opens up potentially new perspectives for the treatment of cancer and age-related diseases.