Dipeptidyl peptidase 2 (DPP2), a member of the dipeptidyl peptidase family, is crucial in intracellular signaling and metabolic regulation. DPP2 is a serine protease, characterized by an active serine site capable of specifically degrading various peptides. The enzyme is primarily located in the cytoplasm, especially expressed in immune cells and certain tumor cells. DPP2 is involved in regulating immune responses, promoting apoptosis, and affecting multiple biological signaling pathways. Its specific gene expression is closely related to its functions in different cell types and physiological states, with mutations potentially leading to metabolic disorders or diseases.