In follow-up investigations on 41 patients with primary cancer of the colon that had been assayed for the presence of steroid-binding activity, six of eight patients whose tumors showed steroid-binding activity for at least one steroid were free of disease one to three years postoperatively. In contrast, only two of 12 patients who had negative binding assay (16%) were free of disease in the same interval. The finding of steroid receptors in human colon cancers does not immediately imply therapeutic advantage. These binding activities may not be receptors, and even if they are, cytoplasmic receptors are a necessary, but not sufficient condition for hormone response. There are, however, sufficient epidemiologic, etiologic, and nutritional observations that seem to link breast and colon cancers to indicate further investigation into the biologic significance of the association of steroid-binding protein in human colon cancer.