Given abnormal levels of MMP9, MMP12 and TIMP3 mRNA expression in tumors from CRC patients and controls, we next measured the level of the MMPs and TIMP3 proteins in human colon cancer epithelial cells compared to normal colon cells by immunoblot (Fig. 3a, Additional file 1: Fig. S3). This evidence concerns the gene TIMP3 and colorectal carcinoma.