A floxed neo cassette was inserted into intron 1, 893 bp upstream of exon 2. This allele, in combination with allele Runx1tm1Buch in the same cells was used for the engineering of T(4;16), a reciporical translocation that replicates the human acute myeloid leukemia (AML) associated translocation, T(8;21). (J:68499)