The theme of immortality in The Immortal Life of Henrietta Lacks is central to understanding the impact of Henrietta's cells, known as HeLa. These cells have achieved a form of immortality through their continuous growth and reproduction, contributing to numerous medical breakthroughs. The book explores the dual nature of this immortality, highlighting both the scientific advancements made possible by HeLa cells and the ethical issues surrounding their use without Henrietta's consent.

HeLa cells symbolize immortality in a literal sense, as they continue to thrive and multiply long after Henrietta's death. This unique property of the cells allowed them to be used in countless studies, aiding in the development of the polio vaccine, chemotherapy, and other medical advancements. Skloot emphasizes this in the opening chapter:

I've tried to imagine how she'd feel knowing that her cells went up in the first space missions to see what would happen to human cells in zero gravity, or that they helped with some of the most important advances in medicine: the polio vaccine, chemotherapy, cloning, gene mapping, in vitro fertilisation. I'm pretty sure that she--like most of us--would be shocked to heart that there are millions more of her cells growing in laboratories now than there ever were in her body.

This passage underscores the vast impact of HeLa cells and the paradox of their immortality, existing in greater numbers now than during Henrietta's lifetime.

Beyond the biological aspect, Skloot's work immortalizes Henrietta Lacks herself. By telling her story, Skloot ensures that Henrietta is remembered not just as a source of cells but as a person with a family and a legacy. The book brings attention to the ethical issues of consent and exploitation, particularly in the context of race and class. Henrietta's status as a poor Black woman played a significant role in how her cells were obtained and used, raising important questions about medical ethics.

Henrietta's immortality is also reflected in the cultural impact of her story. She is remembered through Skloot's book, among her family and friends, and even in music. This multifaceted immortality highlights the enduring significance of Henrietta Lacks, both in scientific research and as a symbol of the need for ethical considerations in medical practices.