Certepetide (CEND-1) is a bifunctional cyclic peptide (a.k.a. iRGD). Certepetide is a tumor-penetrating enhancer via RGD motif interaction with alphav-integrins and via activating NRP-1, and transforms the solid tumor microenvironment into a temporary agent conduit. Certepetide accumulates in tumors, and is used in the research of pancreatic cancer and other solid tumors.