ATR inhibitors, in combination with chemo- and radio-therapy, have been utilized in a synthetic lethality approach to sensitize cancer cells for cell death with varied results (Wagner and Kaufmann, 2010; Toledo et al., 2011; Fokas et al., 2014; Karnitz and Zou, 2015; Lecona and Fernandez-Capetillo, 2018). The gene discussed is ATR; the disease is cancer.