The phosphatidylinositol 3-kinase (PI3K)-like protein kinase ATR (Ataxia telangiectasia and Rad3-related) is central for the maintenance of genome integrity in the context of DNA damage (Cimprich and Cortez, 2008; Zeman and Cimprich, 2014; Sancar et al., 2004) and is also a key protein that prevents the onset of cancer (Bartkova et al., 2005). This evidence concerns the gene ATR and cancer.