MMP9 and neoplasm: Consistent with the in vitro results, mice injected with ESM-1-overexpressing 4T1 cells exhibited significant increases in tumor volume (Figure 6B–D), lung metastasis (Figure 6F), metastasis-related molecules (VEGF, MMP-9, ICAM-1, and VCAM-1), and transcription factors (HIF-1α, phospho-NF-κB, and phospho-STAT-3) (Figure 6H).