Li Cai1*
, Haiyan Huang2,5*
, Seth Blackshaw3,6, Jun S Liu4, Connie Cepko3 and Wing H Wong2,4 
1
Department of Research Computing, Dana-Farber Cancer Institute, 44 Binney Street, Boston, MA 02115, USA
2
Department of Biostatistics, Harvard School of Public Health, 66 Huntington Avenue, Boston, MA 02115, USA
3
Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
4
Department of Statistics, Harvard University, Science Center, 1 Oxford Street, Cambridge, MA 02138, USA
5
Current address: Department of Statistics, University of California, Berkeley, 367 Evans Hall, Berkeley, CA 94720, USA
6
Current address: Department of Neuroscience, Johns Hopkins University School of Medicine, 773 N Broadway Ave, Baltimore, MD 21287, USA