Proteins experience a significantly different environment in vivo than in the context of the idealized dilute environment commonly studied in experiments and simulations. The presence of a high concentration of other macromolecules in the cell (nucleic acids, sugars, lipids, chaperones and other proteins) can dramatically alter protein folding pathways and affect protein-protein interactions. The aim of this workshop is to explore the complications that arise in the cell, with an emphasis on macromolecular crowding, chaperone-mediated folding, membrane-protein interactions and protein aggregation.