The localization of the testosterone-estradiol-binding globulin (TeBG) in prostate, liver and metastatic lymph node cells of a patient with hormone-independent prostatic carcinoma was studied by the triple-layer indirect immunoperoxidase method using anti-human TeBG antibody. The reaction with anti-human TeBG antibody appeared to be localized in the epithelial cells of the original and metastatic tissues of the prostate, and a weakly positive stain also appeared in parenchymal liver cells. The staining of the epithelial cancer cells with anti-human TeBG antibody was uneven, suggesting that the hormone-independent cancer cell population is heterogeneous as far as the localization of the TeBG is concerned.