Activation of the Evi-1 zinc finger gene is commonly associated with the transformation of murine leukemias and is involved in some cases of human AML involving rearrangements at chromosome 3q25. To determine the normal function of the gene, we have looked for expression in a variety of cell lines and tissues. The predominant sites of expression of the gene are in the kidney and ovary. In the kidney, expression is localized to the renal tubules in the corticomedullary junction. In the ovary, high levels of the Evi-1 protein are found in the cytoplasm of developing oocytes. The latter result suggests a potential role for the Evi-1 gene product in early oocyte development.