The immune system is the core of human health, determining whether we survive infancy, which diseases we get, and how long we live. Its secrets, however, have long evaded scientists who are stymied by the sheer scale of this task. Today, AI offers the tools to process the trillions of datapoints required to decode and model the immune system, understand how it varies across individuals, and develop targeted approaches to combatting disease—finally ushering in the era of personalized medicine. This panel introduces a new global collaboration charting the way to longer, healthier lives for all.