Circulating tumor cells are able to stop in small capillaries, engage stable adhesions with endothelial cells and transmigrate through the vessel walls. These are key steps of the metastatic cascade that are still poorly understood. Nonetheless, they directly precede the formation of life-threatening metastases. We develop microfluidic models and use in vivo models to study the fundamental aspect of these steps in relevant biomechanical conditions. Of particular interest, we study the role of filopodia-like protrusions and the adhesion receptors decorating them, as well as the key role of endothelial cells as a barrier against metastatic spreading. The project is running in close collaboration with the Jacquemet lab. This project is supported by two recent and important funding source : JAES foundation until 2025 and the formation of the new Center of Excellence from Academy of Finland – BarrierForce until 2029 !