Don Suddaby / Don Suddaby
Colin Ward / Jake Gimble
LaTanya Richardson Jackson / Nurse Ruth
Jennifer Dundas / Nurse Nancy Jo
William Cameron / Pellerman
Becky Ann Baker / Pellerman's Secretary
Mary Pat Gleason / The Librarian
David Shiner / Clown
Ann Dowd / Pediatrician
Peter Mackenzie / Immunosuppression Doctor
Paul Lazar / Professor Duncan
Laura Linney / Young Teacher
Helena Ruoti / Judalon's Nurse
Luis Ruiz / Judalon's Resident
Joyce Reehling / Columnist
Barbara Poitier / Nikolais' Secretary
Mary Schmidt Campbell / Principal
Michael O'Neill / School Psychologist
William Thunhurst Jr. / Ear Specialist
Ann McDonough / Dietician
Lianne Kressin / Smiling Nurse
Nicolas Petrov / World Bank Executive
Richard Cordery / Suddaby's Senior Manager
Angus Barnett / Suddaby's Junior Manager
Keiko McDonald / Japanese Translator
Vladimir Padunov / Russian Translator
David McFadden / Father Killian
Carmen Piccini / Cristina Odone
Aaron Jackson / Francesco Odone
Neri Kyle Tannenbaum / Female Lab Voice (voice)
Brad Einhorn / Male Lab Voice (voice)
Noah Banks / Lorenzo Odone
Elizabeth Daily / Lorenzo Odone (voice)