While primary tumor burden was not significantly altered between the 4T1-WT and Vcam1-KO groups (Figure 5F), significant decreases in metastatic signals were observed in the lungs of 4T1-Vcam1-KO mice, as detected by biofluorescent imaging and flow cytometry (Figure 5G and Supplemental Figure 14A). Here, VCAM1 is linked to neoplasm.