Scientists have identified a " Highway Code" within cells, a finding that changes the way we perceive how chromosomes move during cell division. Using chromosomes as a model to explain this navigation system, the research team show how this signaling mechanism determines the path through which molecular transporters travel. They have revealed that the existence of specific signals on microtubules -- which work as intracellular highways -- give directions to chromosomes on which route to take in the course of cell division.