[1] Massachusetts Gen Hosp, Ctr Liver, Boston, MA 02114 USA
[2] Massachusetts Gen Hosp, Div Gastroenterol, Boston, MA 02114 USA
[3] Harvard Univ, Massachusetts Gen Hosp, Sch Med, Boston, MA USA
[4] Massachusetts Gen Hosp, Dept Med, Boston, MA 02114 USA
[5] Massachusetts Gen Hosp, Ctr Biostat, Boston, MA 02114 USA