Figure 3.

MMP‐9 overexpression in tumor epithelial cells is a biological marker of colorectal cancer metastasis. Association between MMP‐9 overexpression in tumor cell populations and lymph node involvement (left panels). Compared to those with tumor MMP‐9 downregulation, patients with MMP‐9 overexpression in tumor epithelial, but not stromal, cells exhibit advanced disease stage (middle panels) and increased lymph node tumor burden (right panels). N categories and disease stage scores are specified in Table 2 and are based on the AJCC/TNM system. ¹⁹ ↑MMP‐9 = MMP‐9 overexpression; ↓MMP‐9 = MMP‐9 downregulation. The values in the middle and right panels are means ± SEM. *p <0.05 by the Wilcoxon two‐sample test.