Video 7

Movie S7. Myeloid cells displaying MMP activity take up dextran in an advanced, untreated PyMT/c-fms-EGFP/ACTB-ECFP tumor. MMPSense 680 probe (red) was injected intravenously 24 h before imaging, and labels a large portion of c-fms-EGFP+ myeloid cells (green). Rhodamine-labeled 10 kDa dextran (pink) was injected intravenously 20 min after imaging was started, and can first be seen in blood vessels, then leaking out to the stroma and taken up by the MMPSense+ myeloid cells. Tumor cells are seen in blue.