Eps8 is called the key component of the motor that ensures that dendritic cells, a specialised patrol of the immune system, are activated in moments of danger and run to sound the alarm and activate the body’s cellular defence teams. Without this protein dendritic cells, which monitor organs and tissues for viruses, bacteria parasites and also altered cells, including tumour cells, are still able to sense danger signals, but like amputees, they remain almost immobile and cannot effectively reach the command centres where they should sound the alarm. The disastrous result of their poor ability to move is failure to activate the immune response. The discovery, made by a team of researchers at the IFOM and the IEO in Milan directed by Giorgio Scita and Maria Rescigno, working in collaboration with the University of Milan, is published in the latest issue of the scientific journal Immunity.