One of the major downsides of current cancer diagnosis technologies is that a tumor can often grow to a damaging size by the time imaging methods detect it. That’s why researchers have developed a new method for detecting tiny cancerous tumors that uses of light-emitting nanoparticles that are designed to stick to specific cancer cells. By injecting these nanoparticles intravenously, doctors can detect and track early-stage tumors before it’s too late.