MMP9 and colorectal carcinoma: To further investigate the molecular mechanism underlying the SLC6A14-regulated cell invasion in CRC, we detected matrix remodeling protein expression in HCT116 and Caco2 cells and found that MMP2, MMP9, and MT1-MMP were downregulated by treated with SLC6A14-siRNA or α-MT (Fig. 6A and C).