凯特·伯顿

Kate Burton

饰：Narrator

Donald Coffey

饰：Himself - Johns Hopkins University

Richard Frackowiak

饰：Himself - University College London

Fred Gage

饰：Himself - Salk Institute

John Gearhart

饰：Himself - Stem Cell Researcher

James Patrick Kelly

饰：Himself - Cab Driver

Frederick Meyer

饰：Himself - Surgeon

Louise Osborne

饰：Herself - Cab Driver

Darryl Pearson

饰：Himself - Patient

Inez Pearson

饰：Herself - Patient

Robert Prosser

饰：Himself - Embryologist

David Wesley

饰：Self - Basketball Player

克莱格·文特尔

J. Craig Venter

饰：Self - Biologist