Pharmacological inhibition of NOX4 (GKT137831) (27) and RNAi-mediated knockdown (shRNA and siRNA) (Supplementary Figure 2, F and G, respectively, available online) abrogated TGF-β-dependent ROS production, myofibroblast transdifferentiation (Figure 2, C–G; Supplementary Figure 2, D–J, available online), and cancer cell migration toward conditioned media from treated fibroblasts (Figure 2H;, Supplementary Figure 2K, available online). The gene discussed is NOX4; the disease is cancer.