Dipeptidyl peptidase 9 (DPP9) has been extensively studied for its role in inflammation and cancer. Proteomics analysis identified differentially expressed proteins associated with memory retrieval regulated by DPP9. DPP9-interacting proteins are involved in dendritic spine and axon function, and two memory- and axon-related genes, Tmp3 and Baiap2, were identified as potential targets for DPP9.