T-lymphocytes in CAR-T cells are the natural enemies of tumor cells play an important role in the tumor immune response, and have an extremely strong killing effect on tumor cells. Chimeric antigen receptors (CARs) in CAR-T cells are composed of an extracellular antigen recognition domain (usually a single-chain antibody, but also a peptide or other protein) and an intracellular signaling domain. The extracellular portion of the CAR is used to recognize specific tumor antigens, and the intracellular signaling domain subsequently stimulates T-cell proliferation and elimination of tumor cells through cytolysis and cytokine release.

(1) Personalized treatment: Customized treatment according to the patient's condition allows CAR-T cells to recognize and attack specific types of cancer cells in the patient's body, which helps to improve the accuracy of treatment.
(2) Long-lasting immune effect: CAR-T cell immunotherapy can produce a certain degree of long-lasting immune effect, allowing the immune system to recognize and attack cancer cells for a long period, which helps reduce the risk of recurrence.
(3) Rapid therapeutic response: CAR-T cell immunotherapy produces significant therapeutic effects within a few weeks.
(4) Suitable for refractory and relapsed diseases: CAR-T cell immunotherapy is often applied to diseases that are difficult to control with conventional treatments, especially relapsed leukemia and lymphoma.

CAR-T cell immunotherapy has achieved remarkable success in the treatment of B-cell malignancies, especially acute lymphoblastic leukemia (ALL), chronic lymphocytic leukemia (CLL), diffuse large B-cell lymphoma (DLBCL), primary central nervous system lymphoma (PCNSL), non-Hodgkin's lymphoma, and melanoma, etc. The scope of the treatment is still expanding and being studied.

CAR-T (chimeric antigen receptor T-cell) cell technology is a form of adoptive cellular immunotherapy (ACI). CAR-T cell immunotherapy is a kind of specific immune cell anti-tumor therapy through genetic modification technology, through the chimeric antigen receptor-modified T cells, which can specifically recognize tumor-associated antigens so that the effector T cells' targeting, killing activity, and durability are all higher than that of the routinely applied immune cells, and can overcome the local immune-suppressive microenvironment of the tumor and break the host immune tolerance state.

The core principle of CAR-T cell therapy is to genetically engineer the patient's T-cells to recognize and attack cancer cells. This is accomplished through the following steps of CAR-T cell immunotherapy:
(1) T cells are extracted from the patient's blood;
(2) In the laboratory, researchers design and construct the CAR (chimeric antigen receptor);
(3) The CAR (chimeric antigen receptor) is integrated into the patient's T-cells so that the T-cells acquire the ability to recognize and attack cancer cells;
(4) Large-scale culture and expansion of CAR-T cells to obtain a sufficient number of cells for cancer treatment; (5) Infusion of CAR-T cells back into the patient's body to interact with the cancer cells, releasing cytotoxins and triggering an immune response that destroys the cancer cells.