Movie S6B.

Imaging the presence of tumor-associated class II MHC+ cells using 18F-VHH7 (anti-mouse class II MHC). A WT mouse was inoculated s.c. on the left shoulder with mouse B16 melanoma cells and imaged 7 d postinjection. Tumor cells lack mouse class II MHC molecules. Movies and images are representative of two to four mice with similar results.