Computational Proteomics Unit, Department of Biochemistry, University of Cambridge, Cambridge, UK.|Cambridge Centre for Proteomics, Department of Biochemistry, University of Cambridge, Cambridge, UK.|MRC Biostatistics Unit, Cambridge Institute for Public Health, Cambridge, UK.|Cambridge Centre for Proteomics, Department of Biochemistry, University of Cambridge, Cambridge, UK.|Computational Proteomics Unit, Department of Biochemistry, University of Cambridge, Cambridge, UK.