Generation of ApcΔ580 mice.
ApcCKO heterozygote mice were crossed with Cre deleter mice, EIIA-cre transgenic mice that express Cre in early embryo [35], to knockout the Apc allele in the germline, consequently creating a knockout strain (Figure 1A). The resultant ApcΔ580/+ mice were maintained by backcrossing to C57BL/6J females.