Scientists are creating bacteria to attack cancerous tumors and eat them from the inside. Tumor nuclei lack oxygen, making them an ideal breeding ground for these microbes. The researchers added a genetic tweak that allows the bacteria to survive longer near the edges of tumors exposed to oxygen. This change is triggered only once when sufficient oxygen is present. It is a programmed biological attack aimed at destroying tumors. This approach could offer a new way to fight cancer in the future.[1]