Bioluminescence imaging of major organs and hindlimbs collected at the end of study revealed considerable metastatic cancer signals in kidney, lung, liver, brain, and right hindlimb for both PBS- and CD9-CD38/αCD3-αEGFR Exos-treated animals, but remarkably low extent of metastasis to these sites for mice receiving BP-αCD3-αEGFR-ARC Exos (Fig. 8B–D, and Supplementary Fig. 23). Here, CD9 is linked to cancer.