EGF and cancer: Several authors have shown that ROS act as second messengers and modulate the activity of various processes related to the cytoskeleton, the cell cycle and cell death in cancer and normal cells, such as inhibition of β-transforming growth factor (TGF-β) and epidermal growth factor (EGF), or phosphorylation of histone 2A.X (γH2A.X) (a marker of oxidative DNA damage), among others [55, 56].