CD34 and acute myeloid leukemia: Moreover, miR-9 could promote proliferation of leukemia cells in adult CD34+ AML with normal karyotype by suppressing Hes1 expression and knockdown of miR-9 could reduce circulating leukemic cell counts in peripheral blood (PB) and BM, attenuate splenomegaly and prolong survival in a xenotransplant mouse model [33, 34].