The continuous trafficking of immune cells from the circulation to the site of infection and back is a key aspect of life, as it ensures optimal immune surveillance to fight unwanted pathogens. It enables the right immune cell to be at the right time at the right location. It turns out that one immune cell can help the other in navigating through the vasculature. Like on the highway, one simply follows the neighbour’s car in front of you to bring you home safely. This proposal will identify the key signals that are induced and used by the immune cells to help and follow each other. One of the key factors in this process is the vasculature, or as for our example, the highway you are driving on. The car you are following leaves behind signals at the side of the road. Understanding how these signals are released and how to recognize such signals will eventually bring us home. This new concept in the regulation of the different immune systems will open a whole new field of opportunities to shape and target infectious and inflammation-based diseases.