Although no consensus NF-κB element has yet been identified in the human mmp-3 promoter and the mechanism through which the NF-κB suppresses mmp-3 gene expression in CAFs but not in prostate cancer epithelial cells is yet to be determined, our study identified a preliminary association between ROS-mediated mmp-3 promoter suppression and NF-κB activation in a cell type-dependent manner. The gene discussed is NFKB1; the disease is prostate cancer.