The Sleeping Beauty transposon system promotes lethal malignant progression of BRAFV600E-driven lung tumors in a GEM model. A, Kaplan–Meier survival curve tracking survival of 50 BrafCA and SB (CAGG/R26LSL-SB11) or (BR) mice, either with or without a T2/Onc2 transposon or (BRT) mice donor on chromosome 4 (C4T2/Onc2) for 250 days. Mice were initiated through intranasal instillation with 106 pfu of Ad5.CMV-CRE. Statistical analysis was performed using a log-rank Mantel–Cox test, where P = 0.00000383. B–D, Histological analyses of FFPE tumor-bearing lung sections stained with H&E. E, Expression of SB transposase in BR mouse lung tumors at 19.5 weeks after initiation assessed by immunofluorescence analysis of FFPE sections of mouse lungs. Blue, DAPI-stained DNA; green, SB11 transposase.