A large part of our DNA is made up of selfish DNA elements, some of which can jump from one site in the genome to another, potentially damaging it. Researchers from the Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA) describe how different types of repetitive DNA elements are controlled by the same silencing mechanism in fruit fly ovaries. Central to their findings is an uncharacterized protein that the researchers named “Kipferl”. The findings suggest that different selfish elements compete for the host genome defense system and that Kipferl might be the first of a series of similarly acting molecules yet to be uncovered. The findings are published in eLife.