ATM inhibitors AZD1390 and AZD0156 were generously provided by AstraZeneca via a Materials Transfer Agreement. Both drugs were pharmaceutical grade and were used for the in vivo studies. All in vitro experiments were conducted using AZD1390 (Cat. S8680), AZD0156 (Cat. S8375), Ku-60019 (Cat. S1570), Erastin (Cat. S7242), VE-821 (Cat. S8007), NU7441 (KU-57788, Cat. S2638) from Sellechchem. DMF (Cat. 242926-100G) and TCEP hydrochloride (Cat. C4706-10G) were purchased from Sigma-Aldrich. Etoposide was kindly provided by Dr. Mirit Aladjem’s group.