To test a possible relationship between MIF secretion and malignancy in a panel of breast cancer cell lines, we evaluated the basal secretion of MIF to the culture media using the EpH4-Ev mouse epithelial breast cells as a non-tumorigenic control; B-MEKDD 116, which is a MEK1 transformed and tumorigenic cell line; 67NR, non-metastatic; 66cl4, metastatic to the lung, and 4T1, highly metastatic cell lines. This evidence concerns the gene MIF and breast carcinoma.