A longstanding paradox in cancer biology—why mutations known to drive tumors so often sit quietly in healthy tissue without causing harm—has found a compelling answer in the liver. New research published in Nature reveals that β-catenin mutations, common in hepatocellular carcinoma, are not inherently dangerous but become so only when the tissue surrounding them begins to fail through aging or chronic injury. The threat, it turns out, lives not in the gene alone but in the conversation between a mutation and its deteriorating home.