An innovative tool for the targeted modification of gene activity in heart muscle cells could establish itself as a standard method for research into cardiovascular diseases. Dr. Patrick Laurette and his colleagues at the German Centre for Cardiovascular Research (DZHK), led by Prof. Ralf Gilsbach, have successfully reduced the activity of individual genes in mouse heart muscle cells using the CRISPRi system. This technology allows for the temporary suppression of gene expression without altering the genetic sequence. It thus avoids the potential risks associated with direct intervention in the genome.