MMP2 and colorectal carcinoma: The purpose of this work was to compare the redox status in normal AT (NAT) of individuals without cancer (for whom no cancer was diagnosed) and in AT of patients with CRC adjacent to the tumor (ATAT) and at a distance of 3 cm from it (ATD), activity of matrix metalloproteinase (MMP)-2 and -9 in these tissues, and the impact of TNF-α on them.