The TCR γ/δ protein is a distinctive T-cell receptor （TCR） expressed on the surface of γδ T cells, composed of a γ chain and a δ chain linked by disulfide bonds to form a heterodimer, belonging to the immunoglobulin superfamily. Unlike the conventional αβ TCR, the γδ TCR can directly recognize a broad range of antigens （e.g., phosphorylated metabolites, lipids, stress proteins） without requiring MHC presentation, granting it broader antigen specificity. Its variable （V） region diversity arises from V, （D）, and J gene segment rearrangements, though it exhibits less diversity than the αβ TCR. γδ T cells are primarily found in mucosal tissues, skin, and the gut, playing crucial roles in early immune defense, tumor surveillance, and tissue repair. They can rapidly secrete cytokines （e.g., IFN-γ, IL-17） or exert cytotoxic effects, serving as key effector cells bridging innate and adaptive immunity.