Similar changes in invasion (Fig. 1f) and MMP-7 expression (Fig. 1g and Additional file 1: Figrue S1) were also observed in TPA-treated Caco-2, a well-differentiated and non-invasive colon cancer cell line, and HCT116, another invasive colon cancer cell line. This evidence concerns the gene MMP7 and malignant colon neoplasm.