Explore groundbreaking cancer research in this 16-minute TED talk by Mina Bissell. Discover how her revolutionary experiments challenged prevailing wisdom about cancer growth, demonstrating that a cancer cell's development is influenced by its microenvironment rather than automatically becoming a tumor. Learn about the structure of mammary glands, the role of extracellular matrix, and innovative methods to distinguish between normal and malignant cells. Gain insights into developmental biology and the importance of structural organization in understanding cancer progression.