IREB2 and acute myeloid leukemia: However, the mRNA levels of both ACO1 (IRP1) and IREB2 (IRP2) genes in AML blasts and in non-leukemic CD34+ cells (Figure S3B,C) were not statistically different (t-test p = 0.132 and 0.198 for ACO1 and IREB2, respectively).