Our present findings confirm our hypothesis since: 1) increased MIF serum levels were observed in an additional group of prostate cancer patients when compared to patients with no documented prostate cancer; 2) MIF mRNA was increased in prostate cancer tissue suggesting increased MIF synthesis in prostate cancer; 3) CD74, recently described as a receptor for MIF[11], is localized to prostatic epithelia; 4) prostatic epithelial cells in vitro secrete MIF, with much greater secretion observed in prostate cancer cells. This evidence concerns the gene CD74 and Familial prostate cancer.