Using a powerful single-molecule imaging method they developed, a Broad Institute research team has unveiled a dynamic view of how some cancer-related proteins interact in living cells. The technique relies on highly stable nanoparticle probes that brightly illuminate individual molecules for long periods of time. The researchers used their method to observe, for the first time, individual receptors as they move around the cell membrane, attaching to and then letting go of other receptors to alter signaling within the cell.