To investigate if the observed IR resistance is limited to “stable” cell lines or is a ‘hardwired’ feature of PTEN mutant tumors, we used CRISPR-mediated NSCLC mouse models driven by either mutations of Tp53 and KRas (KP: KRasG12D,Tp53mut) and studied the impact of an additional deletion of Pten (KPP: KRasG12D:Tp53mut:Ptenmut). This evidence concerns the gene PTEN and non-small cell lung carcinoma.