MMP9 and neoplasm: Protein analysis of tumor-cell-derived CM revealed that the overexpression of β-catenin downregulated tumor-promoting genes such as MMP9 30, Runx2 31, and Snail 32, 33, and upregulated a tumor-suppressing gene, p53 34, 35 as well as an apoptosis-inducing factor, TRAIL 36, 37.