At the end of the 4-week period, transplants isolated from the mice maintained on Dox for the full 4 weeks contained predominantly KO + (KRASG12D-expressing) cells (Fig. 4C; right panel) and an accompanying large (100-fold) increase in KRAS transcripts as compared to the tumours obtained from mice given Dox for only the first 2-weeks post-transplant (Fig. 4C, D). Here, KRAS is linked to neoplasm.