The cover image shows a sustainable biorefinery scheme. Cellulose is a renewable and highly available feedstock that is typically found in wood, straw, grass, municipal solid waste, and crop residues. Its use, as raw material for biofuel production, opens a possibility for sustainable biorefinery schemes that do not compete with the food supply. Tapping into this feedstock for the production of biofuels and chemicals requires, as the first step, its depolymerization or its hydrolysis to intermediates more susceptible to chemical and/or biological transformations. Rinaldi and Schüth from the Max-Planck-Institut für Kohlenforschung describe efficient methods for the conversion of cellulose in their Review found on page 1096.