title: Engineering and design Screening, selection and design: standing at the crossroads in three dimensions.
authors.affiliation: Department of Biochemistry and Biophysics Anatomy Chemistry Building 318 University of Pennsylvania School of Medicine Philadelphia, PA 19104-6059, USA wdegrado@mail.med.upenn.edu
authors.initials: WF
authors.lastname: DeGrado
authors.initials: BO
authors.lastname: Nilsson