How does a benign tumor change into a malignant one? No answer universally explains this process. Yet here's the most well-studied reason👇🏻 Wnt pathway activation. That's the kind of signaling protein system to keep cells in a "stem cell" state. That is, in a condition where it can divide. Such a system is needed in the intestine, as an example. Here, the epithelium is renewed with enviable regularity and a "supply" of new cells is needed at regular intervals.