To assess the contribution of NHEJ to DNA DSB repair in cancer stem-like populations of parental and MFR-surviving NSCLC sublines, we analyzed the proportion of DNA-PKcs (S2056) -positive (DNA-PK (S) +) cells irradiated at single doses of 2 Gy and 5 Gy. The gene discussed is PRKDC; the disease is non-small cell lung carcinoma.