In our bodies, proteins carry out almost all essential processes, and protein malfunction causes many diseases. To study the function of a protein, researchers remove it from the cell and subsequently analyze the consequences. The two methods they could typically use currently are genome editing by CRISPR/Cas, and RNA interference. They act on the level of DNA or RNA, respectively. However, their influence on protein amounts is indirect and takes time. Scientists from Germany and the UK now present a new method, called Trim-Away, which makes it possible to directly and quickly deplete a protein from any cell type. As Trim-Away can distinguish between different variants of a protein, it also opens up new venues for the therapy of diseases.