Nothing works without the correct form: For most proteins, there are millions of ways in which these molecules, composed of long chains of amino acids, can be folded - but only one way is the right one. Researchers in the department "Cellular Biochemistry" at the Max Planck Institute for Biochemistry in Martinsried examine how this origami in cells works and what happens if something goes awry. Franz Ulrich Hartl and his team are interested in both the underlying mechanisms and the structure of the molecules involved.