CAR T-cell therapy is a type of treatment that uses a patient's own immune cells to fight cancer. Here's a brief overview of how it works:

1. Collection of T-Cells: First, T-cells (a type of white blood cell that plays a key role in the immune system) are collected from the patient’s blood.
2. Genetic Modification: These cells are then sent to a laboratory, where they are genetically modified to produce special structures called chimeric antigen receptors (CARs) on their surface. These CARs are designed to recognize and attach to a specific protein found on the patient's cancer cells.
3. Expansion of CAR T-Cells: The genetically modified T-cells are grown in the lab until they number in the millions. This process can take a few weeks.
4. Patient Preparation: Before the CAR T-cells are returned to the patient, the patient might receive chemotherapy to help reduce the number of other immune cells in the body. This step helps the CAR T-cells work more effectively.
5. Infusion of CAR T-Cells: The expanded CAR T-cells are then infused back into the patient. Once inside the body, these cells multiply and start to attack the cancer cells.
6. Response Monitoring: After the infusion, the patient is closely monitored to check how the body responds to the therapy. This includes managing any side effects and evaluating the effectiveness of the treatment in reducing cancer.

CAR T-cell therapy has been particularly successful in treating certain types of blood cancers, such as acute lymphoblastic leukemia (ALL) and certain types of lymphomas. However, researchers are also exploring its use in treating other cancers. This therapy is an example of personalized medicine, as it uses the patient's own cells to target their specific type of cancer.