BACKGROUND: To develop the extracellular matrix metalloproteinase inducer (CD147)-targeting therapeutic strategies, accurate detection of CD147 expression in tumors is crucial. Owing to their relatively low molecular weights and high affinities, nanobodies (Nbs) may be powerful candidates for cancer diagnosis and therapy. In this study, we developed a novel CD147-targeted nanobody radiotracer, [ METHODS: CD147 expression in human cancers was detected via immunohistochemistry (IHC) on tissue microarrays (TMAs). Western blot (WB) and flow cytometry were used to screen CD147-positive malignant melanoma (MM), triple-negative breast cancer (TNBC), and pancreatic cancer (PCA) cell lines. The CD147 nanobody (NB147) was labeled with [ RESULTS: TMAs results revealed that CD147 is highly expressed in MM, TNBC, and PCA. A CD147-specific nanobody, NB147, was successfully generated with excellent in vitro binding characteristics. [ CONCLUSIONS: The high expression of CD147 in MM, TNBC, and PCA tissuesand in tumor cells was verified. The CD147 nanobody, NB147 was produced and radiolabeled to obtain the immunoPET probe, [