<i>Apc</i> mutation-induced polyposis in mouse cecum and colon epithelium is dramatically inhibited by concurrent inactivation of one <i>Ctnnb1</i> allele.

<p>(A) The survival of <i>CDX2P-G22Cre Apc</i>^<i>fl/fl</i><i>Ctnnb1</i>^<i>fl/+</i> mice (blue; <i>n</i> = 24) is contrasted with that <i>of CDX2P-G22Cre Apc</i>^<i>fl/fl</i> mice (red; <i>n</i> = 9). <i>P <0</i>.<i>0001</i> by log-rank (Mantel-Cox) test. (B) The survival of <i>CDX2P-CreER</i>^<i>T2</i><i>Apc</i>^<i>fl/fl</i><i>Ctnnb1</i>^<i>fl/+</i> mice (blue; <i>n</i> = 12) is contrasted with that in <i>CDX2P-CreER</i>^<i>T2</i><i>Apc</i>^<i>fl/fl</i> mice (red; <i>n</i> = 14), where time zero represents the third day of three days when TAM was administered daily. <i>P <0</i>.<i>0001</i> by log-rank (Mantel-Cox) test. (C) Hematoxylin and eosin (H&E) staining of proximal colon tissues from a <i>CDX2P-CreER</i>^<i>T2</i><i>Apc</i>^<i>fl/fl</i> mouse 20 days after the third of three daily doses of TAM (left, lower), and a control (non-gene-targeted) mouse (left, upper). Right panels show H&E staining of proximal colon tissues from <i>CDX2P-CreER</i>^<i>T2</i><i>Apc</i>^<i>fl/fl</i><i>Ctnnb1</i>^<i>fl/+</i> mice 20 days (right, upper) or 2 months (right, lower) after TAM dosing. Scale bars, 50 μm.