Figure 1: Schematic representation of Mitochondrial/ROS pathway. TGF-β increases production of mitochondrial reactive oxygen species (ROS) from the electron transport chain complexes (ETC). The ROS play a role in regulation of gene expression associated with EMT through a mechanism involving a thiol reaction in mitochondria. DNA microarray analysis suggests that 15.5% of gene expression is mediated by the Mitochondrial/ROS pathway under TGF-β signaling in mouse mammary gland epithelial cells.