Only ~7% of Cre-injected fish developed T-ALL, and most expressed both dsRED2 and GFP, suggesting leukemic cells had only partial Cre recombination of a transgenic locus harboring multiple rag2:loxP-dsRED2-loxP-EGFP-mMyc copies [40]. This evidence concerns the gene RAG2 and acute lymphoblastic leukemia.