Thus, the targeting and suppression of CTSG by AML1-ETO in t(8;21) AML may provide a mechanism for leukemia cells to escape from the intracellular surveillance system by preventing degradation of foreign proteins..     ///    We report here that CTSG is directly targeted and suppressed by AML1-ETO in t(8;21) acute myeloid leukemia (AML).     ///    "AML1-ETO targets and suppresses cathepsin G, a serine protease, which is able to degrade AML1-ETO in t(8;21) acute myeloid leukemia.. "    ///    "Further evidence shows that CTSG, as a hematopoietic serine protease, can degrade AML1-ETO both in vitro and in vivo. "    ///    Luciferase assays demonstrate that the CTSG promoter is strongly transactivated by AML1 and the AML1-dependent transactivation is suppressed by AML1-ETO. 