According to Defler, how important was the discovery of Hellas cells? Why do you think it was an important discovery?

Hela or hela cell, is a cell type in an immortal cell line used in scientific research around the world. These cells eventually enabled scietists to disvover vaccines for deadly diseases like Polio. They also offered a look into the mechanics of cancer cells. Here is an excerpt from the book:

Her cells were part of research into the genes that cause cancer and those that suppress it; they helped develop drugs for treating herpes, leukemia, influenza, hemophilia, and Parkinson’s disease; and they’ve been used to study lactose digestion, sexually transmitted diseases, appendicitis, human longevity, mosquito mating, and the negative cellular effects of working in sewers. Their chromosomes and proteins have been studied with such detail and precision that scientists know their every quirk. Like guinea pigs and mice, Henrietta’s cells have become the standard laboratory workhorse.