KRAS codon 13 mutations confer reduced oncopotency. A, Schematic outlining the generation of DOX-inducible isogenic MLE-12 and BEAS-2B cells to compare the effect of expressing different mutant KRAS variants on NSCLC initiation. B, Relative viability of isogenic MLE-12 cells 96 hours after DOX-induced expression (100 ng/mL) of each mutant KRAS variant in three different serum conditions – 2%, 0.5%, and 0.1% FBS. Cells were plated in ULA conditions. Viability was analyzed using CellTiter-Glo 3D. Data for each isogenic line are expressed relative to the untreated (no DOX) control of that particular line. n = 3 biological repeats; mean ± SEM. C, Western blotting of isogenic MLE-12 cells 24 hours after DOX-induced expression (100 ng/mL) of each mutant KRAS variant in 0.5% serum. Cells were plated in ULA conditions. Data are representative of five biological repeats for KRAS effector proteins and four biological repeats for KRAS target proteins. Dashed lines indicate that representative blots from three different biological replicates are presented. Vinculin and α-tubulin were used as protein loading controls. D, Quantification of C and associated replicates. For phospho-proteins (KRAS effector blots), phosphorylated protein and total protein run on separate blots were normalized to their respective loading controls on the same blot, and then phospho-protein was normalized to the total protein. Data for each isogenic line were then normalized to the untreated (no DOX) control of that particular line. KRAS target proteins were normalized to the loading control, and then the data were normalized to the untreated (no DOX) control. n = 5 biological repeats for KRAS effector proteins and four biological repeats for KRAS target proteins; mean ± SEM. E, (Left) Timeline of BEAS-2B oncogenicity in vivo experiment using chicken egg xenograft. (Right) Normalized tumor weights measured upon termination of the experiment. Number of eggs indicated per condition. Mean ± SEM reported. Statistical significance between comparisons was calculated using a two-way ANOVA (B, D, and E). ****, P < 0.0001; ***, P < 0.001; **, P < 0.01; *, P < 0.05; ns, > 0.05. A, Created in BioRender. Tinsley, K. (2026) https://BioRender.com/ojsukx1; E, (Left) Created in BioRender. Tinsley, K. (2026) https://BioRender.com/wrfehon.