A few years ago, Professor Kathrin de la Rosa and her colleagues in the lab of the Swiss immunologist Antonio Lanzavecchia made an unusual discovery. The team found antibodies in the blood of malaria patients that had been made according to the blueprint of a gene that actually had a totally different function. “This gene usually codes for a receptor that inhibits the immune system, which the malaria pathogen may target to reproduce more easily,” explains de la Rosa, who directs the Immune Mechanisms and Human Antibodies Lab at Berlin’s Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC) and the Berlin Institute of Health at Charité (BIH).