Abstract: CD26, as a T cell surface antigen and a costimulatory molecule, is involved in the whole process of T cell maturation, activation and the realization of immune effect. In many related immune diseases of human, including autoimmune diseases, inflammatory diseases, cancer and so on, CD26 plays an indispensable role through the immune regulation of T cells.

Key words: CD26, DPPⅣ, T cell, immune regulation