Carole LaBonne , 2025-05-19 08:30:00
Imagine a world without lifesaving medicines, preventive care, or therapies — no insulin for diabetes, no vaccines for polio, and fewer (if any) options for treating cancer. What do these amazing medical achievements have in common? They all depended heavily on research using animals, the behind-the-scenes heroes of medical breakthroughs.
Animal models play a starring role in medical discoveries because they help scientists understand how living organisms develop and function, and how they respond to diseases and treatments. Diseases like cancer, diabetes, and Alzheimer’s are incredibly complicated. They involve many different parts of the body working together — or sometimes failing to do so. Researchers simply can’t get the full picture from cells in a dish or computer models alone. That’s where animals, such as mice, zebrafish, chickens, and frogs, step in.
Let’s rewind to 1923. Frederick Banting and John Macleod won the Nobel Prize for discovering insulin, a groundbreaking treatment for diabetes, thanks to their research on animals. Before their discovery, diabetes was practically a death sentence, treatable only by continuous near starvation of the patient. Likewise, Jonas Salk’s polio vaccine, developed with studies involving animal models, transformed polio from a terrifying epidemic into a disease now almost entirely eradicated.
Fast-forward to 2018, when James Allison and Tasuku Honjo won the Nobel Prize for pioneering cancer immunotherapy. They discovered special proteins that stop our immune systems from attacking cancer cells — findings that, like earlier cancer treatments, were only possible because of studies with animal models. Thanks to their work, countless patients today benefit from revolutionary cancer treatments.
It is not just mammals playing crucial roles in research. Zebrafish, with their see-through embryos, have helped scientists explore genetic diseases, birth defects, and new medications. Chick embryos have been central to understanding early growth and how organs form, solving mysteries of developmental biology. Xenopus frogs, famous for their large eggs, have clarified how cells divide, communicate with each other and give rise to organs and organisms, providing essential insights into many areas of biology. Indeed, John Gurdon was awarded a Nobel Prize in 2012 for his pioneering work with Xenopus demonstrating that the nuclei of differentiated cells could be reprogrammed to pluripotency — a finding that laid the groundwork for cell-based therapeutics.
Moreover, animal models have dramatically enhanced our understanding of birth defects, from which more children die from than cancers. These animal models have illuminated genetic mutations and developmental problems leading to conditions such as neural tube defects, including spina bifida, and congenital heart defects, improving our ability to prevent and treat these conditions earlier and more effectively.
Despite these high impact contributions, the National Institutes of Health, under the nascent leadership of Director Jay Bhattacharya, recently announced that it plans to prioritize “human-based science while reducing animal use in research.” Health and Human Services Secretary Robert F. Kennedy Jr. defended this in recent congressional testimony, claiming that “we can accomplish a lot of those goals on safety and efficacy with AI technology.” However, while AI and other non-animal research methods—such as computational models, advanced cell cultures, and organ-on-chip technologies, represent exciting progress, it is important to stress that they complement rather than replace animal models. Animal research remains crucial for understanding the complex biological interactions impacted by syndromes and diseases and is essential for discovery-based science.
Recent advancements in basic science using animal models have provided crucial insights beyond traditional mammalian studies. Zebrafish research recently uncovered genetic pathways involved in spinal cord regeneration after injury, offering hope for regenerative medicine applications. Frog embryos continue to be critical in studying embryonic brain development, shedding light on developmental disorders like autism and congenital heart defects, helping scientists uncover novel therapeutic targets.
Indeed, animal models are becoming even more important and valuable because of recent breakthroughs in single-cell biology. Technologies like single-cell RNA sequencing and spatial transcriptomics allow scientists to analyze gene expression patterns and cellular behaviors at an individual cell level. These powerful tools, when combined with animal models, are empowering groundbreaking discoveries. For example, single-cell RNA sequencing studies in zebrafish have revealed detailed cellular processes underlying heart regeneration, providing insights that could revolutionize treatments for human heart disease. Similarly, spatial transcriptomics has helped scientists map complex cellular interactions during embryonic development in chick embryos, enhancing our understanding of tissue formation and organ growth.
Scientists are strongly committed to responsible and compassionate research and most who study biology do so because of their love of animals. They constantly seek ways to use fewer animals, minimize stress, or avoid use of animals altogether whenever possible. Moreover, vertebrate animals (those with backbones) are carefully protected under the law and can be used for research only with careful regulatory oversight. Unlike the much greater numbers of animals grown for food, research animals are covered by the Animal Welfare Act, which mandates ethics-committee review, veterinary oversight, and pain mitigation. And although in-silico and organ-on-a-chip methods can now complement this animal work and may eventually replace some of it, animal research remains indispensable for generating new discoveries about how living system develop and function, as well as to support medical progress.
The truth is clear: Animal models aren’t just helpful; they’re irreplaceable. They remain central to understanding the complexities of biology and disease, paving the way for discoveries that continually improve—and save—human lives.
So the next time you benefit from medical treatments, spare a thought for the research animals that drove those discoveries — it is their contributions that continue to make Nobel Prize-winning medical breakthroughs a reality.
Carole LaBonne is president of the Society for Developmental Biology and the Erastus Otis Haven professor of molecular biosciences at Northwestern University.
