TCR α/β (T-cell receptor α/β heterodimer) is a core molecule of the adaptive immune system, formed by the disulfide bond linkage of α and β transmembrane polypeptide chains. It is present on the surface of most mature T cells and non-covalently associates with the CD3 complex to form the complete T-cell receptor (TCR-CD3 complex). Its primary function is to recognize antigen peptides presented by major histocompatibility complex (MHC) molecules. The genes encoding TCR α/β undergo V(D)J recombination, generating an extraordinarily high degree of diversity, enabling the immune system to recognize a vast array of antigens. TCR α/β plays a decisive role in T-cell development, activation, clonal selection, and immune responses, making it a fundamental target in immunology research and a key molecule in tumor immunotherapy, such as TCR-T therapy.