The present disclosure relates to methods of identifying a cancer having sensitivity to an ATR inhibitor compound, and treating subjects with such identified cancers with the ATR inhibitor, particularly in combination with a DNA damaging agent.本發明係關於鑑別對ATR抑制劑化合物具有敏感性之癌症,及用該ATR抑制劑,特別與DNA損壞劑組合治療患有此鑑別癌症的受試者之方法。