Several members of the Ets transcription factor family are involved in tumour progression. They share a unique DNA-binding domain, the Ets domain, which specifically recognizes GGAA/T-containing sequences common in many promoters. While the roles of quite a number of Ets proteins in carcinogenesis have been well established, little is known about the importance of the Ets protein Elf-1 (E74-like factor 1) in cancer. Immunohistochemical analysis of breast cancer biopsies showed a negative correlation of Elf-1 expression with histological grading, lymphnode metastasis and tumour stadium. However, no association of Elf-1 expression with clinical outcome was observed. Western blot analysis of cytosolic breast cancer extracts show a correlation of Elf-1 expression with the expression of uPA and PAI-1, which are relevant for increased malignant potential and poor patient outcome in breast cancer. These data suggest that Elf-1 may modulate breast cancer progression to some extent without having an impact on survival of breast cancer patients.