T-cell transfer therapy, also known as adoptive cell therapy (ACT), is an immunotherapy approach that involves collecting and enhancing a patient’s T-cells to improve their ability to fight cancer. The modified T-cells are then expanded in the lab and reinfused into the patient. This therapy includes treatments like CAR T-cell therapy and TIL (tumor-infiltrating lymphocyte) therapy. T-cell transfer therapy aims to harness the immune system to target and destroy cancer cells more effectively.