ATM and neoplasm: Although the efficacy of ATM inhibitors such as KU-55933, KU-60019, KU-59403, CP-466722, AZ31, AZ32, AZD0156, and AZD1390 has been demonstrated in different tumor types showing different responses to RT in preclinical studies (28, 66–68), systematic and comprehensive testing is lagging in CRC (7).