Furthermore, we saw no apparent selection for loss of the remaining wild type Apc allele in tumors arising in CDX2P-CreERT2 Cdx2fl/fl BrafCAApcfl/+ mice, as no β-catenin nuclear or cytoplasmic staining was seen in the CDX2P-CreERT2 Cdx2fl/fl BrafCA Apcfl/+ mouse tumor tissues studied (Figure 2—figure supplement 1E). This evidence concerns the gene APC and neoplasm.