Supercomputer simulations have uncovered how the molecular motor kinesin navigates along microtubules, which are long, thread-like structures found inside cells. Kinesin acts like a tiny delivery truck, carrying important cellular cargo by taking step-by-step movements along these microtubules. To move efficiently and stay on track, the motor's two "feet" must coordinate their steps in a precise way. Scientists have long known that a flexible region called the neck is important for this coordination, but the exact shape of the neck and how it interacts with the microtubule have been unclear due to the limitations of current imaging methods. To overcome these challenges, a research team created an atomic-level model of the kinesin motor attached to a microtubule—a system made up of about 3 million atoms—and used the supercomputer Fugaku to simulate its movement. They employed a computational technique called generalized replica exchange with solute tempering (gREST), which allows researchers to explore complex molecular movements more efficiently. Using two different models of molecular forces (force fields), they determined the most stable structure of the flexible neck region. They then simulated the motor's first step using a simplified model where parts of the microtubule were artificially removed to mimic a step. The simulations revealed that the neck region forms a twisted, two-strand spiral known as a coiled coil, which lies perpendicular to the microtubule and stays in close contact with its surface. When modeling the motor's stepping motion, the researchers found that the neck's interaction with the microtubule strongly influences the direction of the stepping motion. Instead of moving directly over the front foot, the rear foot moves around the right side of the front foot in a counterclockwise path. This specific interaction between the neck and the microtubule is essential for forward movement. Other neck configurations that had weaker interactions with the track failed to move forward, highlighting the importance of this precise structure. These findings provide new insight into how kinesin controls its movement at the atomic level, explaining how local structural details determine the direction of motion. This study offers a critical foundation for further research on how cells transport materials. However, the researchers note that their model has some limitations, including using a shortened version of kinesin, artificially triggering steps by removing parts of the microtubule, and not including flexible elements on the microtubule surface. Future studies that incorporate full-length kinesin and more realistic microtubule structures will help refine and expand this understanding.