PTEN and adenoma: By exploiting the capacity of the transgenic gpA33:CreERT2 driver to restrict tamoxifen-inducible DNA-recombinase activity to the adenomatous epithelium in the stomach of Gp130F/F mice [37], we observed that the tamoxifen-induced deletion of Pten in 8-week old gpA33:CreERT2;Gp130F/F;Ptenfl/fl compound mice produced significantly larger adenomas 4 weeks later (Figure 5C).