The Immortal Life of Henrietta Lacks by Rebecca Skloot begins with a Prologue in which Skloot discusses how she became interested in the story of Henrietta Lacks. She describes taking a course in biology from Professor Donald Defler at a community college. During a lecture, Defler talked about how biologists had spent many years trying to make human cells reproduce outside the body so that it would be possible to study human cellular biology in the laboratory. The HeLa line of cells were the first human cell line that reproduced successfully outside the body and thus enabled scientists to do breakthrough research especially in the area of studying cancer. The use of tissue cultures is extremely important in the early stages of discovering and testing drugs.