Figure 7b:

⁸⁹Zr-oxine–labeled OT-1 CTLs migrated to B16-OVA tumor. (a) MicroPET/CT images of ⁸⁹Zr-oxine–labeled OT-1 CTLs in RAG1 knockout mice bearing B16-OVA melanoma tumor revealed migration of a small fraction of CTLs to the tumor (arrows) (representative images of six experiments). (b) Graph shows activity accumulated in the tumor quantified in a increased over time. (c) B16-OVA tumors regressed after the transfer of ⁸⁹Zr-oxine–labeled activated OT-1 CTLs, indicating that the labeled OT-1 CTLs maintained their cytotoxic function (n = 6). Untreated mice were sacrificed on day 7, as the tumor diameter reached 20 mm (n = 5). * P = 2.84 × 10⁻⁵ on day 7 according to Holm-Sidak multiple tests that included three tests corresponding to days 2, 5, and 7. Error bars indicate standard deviations.