Human skin is a remarkable organ serving as a barrier protecting us from pathogens, toxic substances and others. Our skin needs to constantly renew throughout our lifetime as well as change its size to perfectly fit and cover the body. To fulfill such a complex and dynamic behavior every cell within the skin has a specific task dependent on its position. Scientists from the Max Planck Institute for Biology of Ageing in Cologne have now shown that cell density and crowding play a critical role in instructing single stem cell fate decisions and movement of differentiating cells upwards within the tissue. This ensures that all cell types are correctly positioned within the tissue.