Cancer cells can survive treatment by changing their identity or behavior, not just by acquiring mutations. This review examines how these flexible states allow tumors to bypass the biological pathways that cancer drugs target. Some changes are reversible: cells may become sensitive to a drug again after treatment stops. Over time, however, genetic changes can build up and make resistance permanent. The authors discuss emerging strategies to prevent these adaptable cells from appearing or eliminate them once they do. The practical message is that understanding a tumor's changing behavior may matter alongside identifying its mutations. This is not evidence that patients should interrupt treatment. The summary is based on the abstract only, which provides no specific treatment outcomes. All authors are Genentech employees and own Roche shares.
