T-cell therapy is a type of cancer treatment that involves modifying a patient's own T cells (a type of immune cell) to better recognize and attack cancer cells. This approach often involves extracting T cells from the patient, genetically engineering them to express a specific receptor that targets cancer cells, and then reinfusing these modified T cells back into the patient. T-cell therapy has shown promising results in treating certain types of cancers, particularly blood cancers like leukemia and lymphoma. It is a form of immunotherapy that aims to harness the power of the immune system to fight cancer.