(a) Kaplan-Meier analysis of mouse survival following thoracic irradiation and imatinib treatment. Death was considered complete (cause-specific due to radiation) in all cases except those of planned euthanasia for histological assessment, which were considered as censored. Radiation (20 Gy) reduced survival (P < 0.001 vs. the control as reported in (24)). Imatinib treatment increased mouse survival if administration started as late as 2 weeks after radiation (P < 0.02 vs. radiation) and if started early within 3 days after radiation (P < 0.01 as reported in (24)). The earlier start of drug treatment tended to be more effective in prolonging survival than later start of drug treatment, but this difference was not significant (P > 0.1). (b) Bodyweight follow-up after thoracic irradiation and imatinib treatment. Five mice were randomly selected in each group and weighed every two weeks. Mean ± SE was presented. * P < 0.01 vs. the RT only group; # P < 0.01 vs. the control group.