Bioinformatics Division, Walter + Eliza Hall Institute, 1G Royal Parade, Melbourne, 3050, Australia. freytag.s@wehi.edu.au.|Department of Statistics, University of California, 367 Evans Hall, Berkeley, 94720, USA. johann@berkeley.edu.|Bioinformatics Division, Walter + Eliza Hall Institute, 1G Royal Parade, Melbourne, 3050, Australia. terry@wehi.edu.au.|Bioinformatics Division, Walter + Eliza Hall Institute, 1G Royal Parade, Melbourne, 3050, Australia. bahlo@wehi.edu.au.