Author information:
(1)Department of Biostatistics and Computational Biology, Dana-Farber Cancer 
Institute and Harvard T.H. Chan School of Public Health, Boston, MA, 02215, USA.
(2)Division of Hematology/Oncology, Boston Childrens Hospital and Department of 
Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, 
Boston, MA, 02215, USA.
(3)Department of Pediatrics, Childrens Medical Center Research Institute, 
University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
(4)Howard Hughes Medical Institute, Boston, MA, 02215, USA.
(5)Department of Pediatrics, Childrens Medical Center Research Institute, 
University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA. 
jian.xu@utsouthwestern.edu.
(6)Department of Biostatistics and Computational Biology, Dana-Farber Cancer 
Institute and Harvard T.H. Chan School of Public Health, Boston, MA, 02215, USA. 
gcyuan@jimmy.harvard.edu.