Scientists have uncovered a surprisingly simple “tissue code”: five rules that choreograph when, where, and how cells divide, move, and die, allowing organs like the colon to remain flawlessly organized even as they renew every few days. Mathematical models showed that manipulating just these parameters faithfully recreates real tissue architecture, hinting that the same code may govern skin, brain, and more. The discovery offers a fresh way to understand healing, birth defects, and cancer, and could supercharge initiatives such as the Human Cell Atlas by turning static cell maps into dynamic predictions.