FAP and neoplasm: As shown in Fig. 6A, B, compared to control group, 131I-FAP-2286 TRT markedly reduced the uptake of 18F-FDG in tumor (SUVmax: 2.29 ± 0.16 vs 1.68 ± 0.08, P < 0.01), but the lowest SUVmax of tumor was observed in 131I-FAP-2286 + 3-MA group.