[1] Hosp Sick Children, Resp Med, Toronto, ON, Canada
[2] Univ N Carolina, Pediat Pulmonol, Chapel Hill, NC 27515 USA
[3] Hosp Sick Children, Translat Med, Toronto, ON, Canada
[4] Univ N Carolina, Dept Pediat, Chapel Hill, NC 27515 USA
[5] Univ N Carolina, Mars Lung Inst, Chapel Hill, NC 27515 USA
[6] North Carolina Childrens Hosp, Dept Pediat, Chapel Hill, NC USA
[7] Hosp Sick Children, Child Hlth Evaluat Sci, Toronto, ON, Canada
[8] Washington Univ, Sch Med, Pediat, St Louis, MO USA
[9] Univ N Carolina, Cyst Fibrosis Res & Treatment Ctr, Marsico Lung Inst, Chapel Hill, NC 27515 USA
[10] Stanford Univ, Pediat, Palo Alto, CA 94304 USA
[11] Seattle Childrens Hosp, Pulm Med, Seattle, WA USA
[12] Univ Colorado, Sch Med, Pediat, Aurora, CO USA
[13] Univ N Carolina, Sch Med, Dept Pathol Lab Med, Chapel Hill, NC 27515 USA
[14] BC Childrens Hosp, Pediat, Vancouver, BC, Canada