Resumo em inglês The generation of reactive oxygen species (ROS) may be both beneficial to cells, performing functions in intracellular signaling and detrimental, modifying cellular biomolecules. ROS can cause DNA damage, such as base damage and strand breaks. Organisms respond to chromosome insults by activation of a complex and hierarchical DNA-damage response pathway. The extent of DNA damages determines cell fate: cell cycle arrest and DNA repair or cell death. The ATM is a central pr (mais) otein in the response to DNA double-strand breaks by acting as a transducer protein. Collected evidences suggest that ATM is also involved in the response to oxidative DNA damage.