In conclusion, this study demonstrates that metformin inhibits LCA-induced IL-8 upregulation by suppressing NADPH oxidase, an important enzyme in ROS production, and NF-κB activation in HCT116 CRC cells and diminishes endothelial cell proliferation and tubelike formation in tumor microenvironments. The gene discussed is NFKB1; the disease is colorectal carcinoma.