Jean-David Zeitoun’s book Le gène qui ne voulait pas mourir challenges the common belief that family traits are determined only by genetics. The book opens with the stories of three patients—Olivier, Élodie, and Anthony—each dealing with inherited conditions such as hemochromatosis, Crohn’s disease, and colorectal cancer. Zeitoun uses these cases to explore how much of our lives is shaped by our genes, arguing that heredity involves more than just DNA. He suggests that factors like behavior, environment, and culture also play a significant role in passing down characteristics from one generation to the next. The author critically examines commonly used scientific methods like twin studies and genome-wide association studies (GWAS), which he believes oversimplify the complexity of inheritance. Zeitoun points out that while DNA is important, it is not the only factor in shaping who we are. He argues that "our parents give us much more than half of their chromosomes," emphasizing that environment and personal experiences also contribute to our identities. Le gène qui ne voulait pas mourir has been praised for making complex scientific ideas easier to understand for a general audience. However, some critics note that the book’s tone becomes more argumentative as it progresses, especially when discussing the role of medicine and the limits of genetic determinism. Zeitoun’s work ultimately presents heredity not as a fixed destiny but as an ongoing exploration of how biology and lived experiences interact to shape our lives. Zeitoun’s approach invites readers to rethink the idea that our genes alone determine our health, behavior, and identity. By highlighting the influence of environment and culture, he encourages a more nuanced view of inheritance that goes beyond the traditional understanding of genetics. The book serves as both a scientific analysis and a philosophical reflection on what it means to be shaped by our past.