Glowing dye reveals hidden clues in esophageal cancer

This study tested a new imaging technique to see a protein called PD-L1 in esophageal cancer tumors. PD-L1 helps doctors decide if immunotherapy might work, but current tests are not always accurate. Researchers gave 21 patients a special fluorescent dye that attaches to PD-L1, then used a camera during an endoscopy to see where the protein is located. The goal was to check if this method is safe and can show how PD-L1 varies within a tumor, which could help better select patients for immunotherapy in the future.