Networks of gene families of the seven analyzed plant species that are associated with the CesA genes Plants have neither supportive bone tissue nor muscles, and yet they can form rigid structures like stalks and even tree trunks. This is due to the fact that plant cells are enveloped by a stable cell wall. The main component of the plant cell wall is cellulose, which represents almost 50 percent of the total cell wall material and, at one billion tonnes per year, is the most frequently produced macromolecule in nature. Very little is known about the way in which cellulose is produced, and the knowledge that is available has mainly been obtained from the model plant thale cress (Arabidopsis thaliana) which, although easy to study, is of no economic significance. Staffan Persson and his research group at the Max Planck Institute of Molecular Plant Physiology have succeeded in showing that knowledge obtained in Arabidopsis can be applied to other plant species and even advanced.