Computational Biology and Bioinformatics Program, Duke University Medical Center Box 90090 Duke University, Durham, NC 27708-0090, USA.|Computational Biology and Bioinformatics Program, Duke University Medical Center Box 90090 Duke University, Durham, NC 27708-0090, USA.|Computational Biology and Bioinformatics Program, Duke University Medical Center Box 90090 Duke University, Durham, NC 27708-0090, USA.