In this study, we examined the impact of two different MFR regimens, fraction dose escalation (FDE) in the split course and conventional hypofractionation (HF), on the phenotypic and molecular signatures of two IR-surviving NSCLC cell sublines derived from parental A549 (p53 wild-type) and H1299 (p53-null) cells. Here, TP53 is linked to non-small cell lung carcinoma.