MMP9 and neoplasm: In tumor, another prevalent subset of stromal cells is CAFs that interact with tumor cells through oxidative stress and NF-κB activation to secrete plenty of cytokines (e.g., IL-6, IL-8, IL-10, and IFNγ), growth factors (e.g., basic fibroblast growth factor (FGFβ) and TGFβ2), and other factors (e.g., MMP-2, MMP-9, and fibronectin) [297, 298].