All cells were seeded such that they reached no greater than 60–70% confluence at the time of treatment. Media was changed every 2–3 days following treatment. Irradiation was performed under ambient oxygen using a Cs-137 Gammacell irradiator (Nordion) at a dose rate of ~0.8Gy/min. Inhibitors were added 1h before treatment and maintained until collection unless otherwise noted: DNA-PKi (NU-7441, 2µM, Tocris), CDK1i (RO-3306, 9µM, Tocris), Ruxolitinib (1µM, Cayman Chemicals), PLK1i (BI-2536, 10nM, Selleck Chemicals), Aurora Bi (AZD1152-HQPA, 10nM, Selleck Chemicals), CDK1/2/4i (R547, 0.6µM, Cayman Chemicals), CDK4/6i#1 (PD332991, 1µM, Cayman Chemicals), CDK4/6i #2 (LY28352169, 2.5µM, Cayman Chemicals) and ATMi (Ku55933, 10µM, Selleck Chemicals). PARPi (AZD-2281, 5µM, LC Laboratories) was added to UWB1.289 cells and kept on for the duration of the 6 days before harvesting. IFNβ1 (Peprotech) was added to cells at 2.5ng/mL for 4h before harvesting. 2’3’-cGAMP (InvivoGen) was added to the cells at a concentration of 10 µg/mL for 8 hours before harvesting. For nuclease induction cells were incubated in Shield-1 (1µM, Chemipharma) and 4OHT (2µM, Sigma) were added for 6h before washing twice with PBS and adding back media without drugs to allow recovery. For synchronization experiments cells were incubated in CDK1i for 16h then irradiated as necessary. Immediately following irradiation media was removed, cells washed twice in PBS and media without CDK1i was added for an appropriate duration. Herring testis DNA (Sigma) was dissolved in water and transfected into cells at the indicated concentrations using JetPrime reagent (Polyplus Transfection) according to manufacturers protocols.