Researchers at Washington University in St. Louis are working on a photothermal treatment to destroy tumors. The research is published in Small. The team, led by Younan Xia, uses gold nanocages, which are injected into the body and selectively accumulate in tumors. Later on, the tumors are bathed in laser light. The surrounding tissue is barely warmed, but the nanocages convert light into heat, killing the malignant cells.