Furthermore, MMPs may affect the redox conditions in the tumor microenvironment and vice versa, as, for example, MMP-2 and MMP-9 are upregulated by NOX/ROS-dependent NFκB activity [236,237], whereas MMP-3 activation induces mitochondrial ROS production and NADPH oxidase 1 (Nox1) [238]. This evidence concerns the gene NOX1 and neoplasm.