“Can a cell learn?”

Ever since the genetic code was deciphered, we have increasingly come to view cellular control through the lens of genetic determinism. In this paradigm, a cell’s fate is already written into its DNA, which is in turn shaped by Darwinian evolution over the course of many generations. At the same time, an essential part of our experience as human beings is our ability to learn: our past shapes our present in a multitude of ways, all within a single lifetime. Is it possible that cells can adapt to their environment by learning, thereby overcoming their genetic destiny? We explore this possibility by tracing the life history of individual cells. In the context of drug resistance in cancer, we show that there is a special subset of cells that can store memories of past events. These memories allow cells to rewire themselves at the molecular level to adapt to challenges that evolution may have never encountered. We posit that cellular learning may be occurring across many biological systems, affording new opportunities for the engineering of cellular behavior.