Bordetella pertussis is the agent responsible for whooping cough, a disease that is currently on the rise. In particular, the bacterium produces the CyaA toxin. A consortium including several teams from the Institut Pasteur, CNRS, and Sorbonne University, working closely with the C2RT Proteins Pole technical cores and several SOLEIL and ESRF synchrotron light lines, has examined the entry mechanism of the CyaA toxin in target cells. This work has revealed a membrane translocation mechanism that has proved very useful in terms of knowledge of living biology.