MX1 and acute lymphoblastic leukemia: Because Dnmt3aKO T-ALL cells were hypersensitive to IL-6, and both pSTAT3 and pSTAT5 were elevated, we crossed mice with inactivating floxed alleles of IL-6rα,33Stat3,34 and Stat535 to Mx1-Cre:Dnmt3afl/fl mice.