Despite employing polar tridentate ligands with a bis((1-(carboxymethyl)-1H-imidazol2-yl)methyl)amino donor group for chelation of [99mTc][Tc(CO)3]+, the significant lipophilicity of the tricarbonyl complex, as observed in PSMA ligands or somatostatin receptor–targeted compounds (Lu et al. 2013; Maresca et al. 2010), leads to hepatobiliary elimination of FAPI-19, resulting in a limited tumor accumulation. The gene discussed is FOLH1; the disease is neoplasm.