– DOTA-NI-FAPI-04 is an FAP inhibitor (IC50 = 7.44 nM). By integrating FAP targeting with hypoxia-sensitive groups (nitroimidazole), DOTA-NI-FAPI-04 significantly enhances tumor uptake and retention. Through DOTA chelation with metal isotopes (such as 68Ga and 177Lu), it forms radioactive probes ([68Ga]Ga/DOTA-NI-FAPI-04 and [177Lu]Lu/DOTA-NI-FAPI-04) useful for research in tumor diagnosis and therapeutics. This compound exhibits dual-targeting potential in cancer imaging, tumor microenvironment analysis, and radionuclide therapy, particularly in scenarios involving the interaction between tumor stroma and hypoxic regions.