Immunofluorescent staining of VE-cadherin (A), ZO1 (C), and MMP9 (E) in HCmel12 subcutaneous tumors from wild-type and CD93–/– mice treated with DC101 or isotype control (ISO). Scale bars: 20 μm. (B, D, and F) VE-cadherin (B), ZO1 (D), and MMP9 (F) expression was quantified and normalized to the CD31+ area. Wild-type ISO (n = 6–8), CD93–/– ISO (n = 7–9), wild-type DC101 (n = 7–10), and CD93–/– DC101 (n = 4–6). *P < 0.05; **P < 0.01; ****P < 0.0001 by 1-way ANOVA with Tukey’s multiple-comparison test. NS, not significant. All immunofluorescence quantifications were performed in a minimum of 5 fields of view/sample. (G) Percentage of mice that developed lung metastasis after subcutaneous inoculation of HCmel12 cells. Wild-type ISO (n = 10), CD93–/– ISO (n = 9), wild-type DC101 (n = 10), and CD93–/– DC101 (n = 10). (H) Metastatic burden per mouse (percentage of lung tissue area covered by metastases). Wild-type ISO (n = 10), CD93–/– ISO (n = 9), wild-type DC101 (n = 10), and CD93–/– DC101 (n = 10). *P < 0.05, **P ≤ 0.01 by 1-way ANOVA with Tukey’s multiple-comparison test.