
Scientists Banting, Best, Collip and Macleod at the University of Toronto as they race for a treatment to cure 13-year-old Leonard Thompson of his life-threatening diagnosis of diabetes.

as Dr. Frederick Banting

as Leonard Thompson

as Nurse Anna

as Nurse May

as Mr. Thompson

as John Macleod

as James Collip

as Charles Best

as Dr. Walter Campbell

as Little Girl's Mother

as Narrator (voice)