Scientists have known for decades that genes can be transferred from one species to another, both in animals and plants. However, the mechanism of how such an unlikely event occurs remained unknown. Now, researchers from Alejandro Burga’s lab at the Institute of Molecular Biotechnology (IMBA) of the Austrian Academy of Sciences identify a vector of horizontal gene transfer (HGT) in worms. The findings, published on June 29 in Science, could lead to the discovery of further vectors of HGT in eukaryotes and might find applications in pathogen control.