Overexpression of the EVI1 oncogene is associated typically with aggressive myeloid leukemia, but is also detectable in breast carcinoma where its contributions are unexplored.
Thus, it is likely that overexpression of the zinc finger protein lacking the PR domain (EVI1 and MEL1S) in the leukemia cells is one of the causative factors in the pathogenesis of myeloid leukemia.
In contrast to MDS1/EVI1, EVI1 is often activated inappropriately by chromosomal rearrangements at 3q26 leading to inappropriate expression of the protein in hematopoietic cells and to myeloid leukemias, which are often characterized by abnormal megakaryopoiesis.
Constitutive expression of Evi-1 in hematopoietic cells, which is caused by retroviral insertions or chromosomal translocations and inversions, is closely associated with myelogenous leukemias and myelodysplastic syndromes in mice and humans.
This translocation results in the fusion of TEL, a recently described ETS-like gene on 12p13, and AML1, which was shown to be involved in the formation of fusion genes with ETO and EVI1 in myeloid leukemias.