The essential aim is to determine if malignant endometria produce progesterone-specific proteins that can be detected by radioimmunoassay and provide a diagnostic test for malignant neoplasia or an indicator of the responses of a neoplasm to hormonal therapy. In order to do this we must: (a) isolate and purify proteins that are synthesized by the normal human endometrium and secreted into the lumen of the uterus during the progestational phase of the menstrual cycle; (b) develop a rapid and specific chemical test for the detection and quantitation of these materials in biologic fluids; (c) determine the influence of progesterone and other steroids on the direct stimulation of de novo synthesis and/or secretion of these proteins from the endometrium; and (d) identify which of the the several cell types found in normal endometria synthesize these proteins. The secretory proteins will be isolated from uterine washings using molecular sieve and ion exchange chromatography. Purified products will be used as antigens in the rabbit. Antibodies will be used as reagents in immunoprecipitation and immunocytochemical assays on biological fluids and tissue sections. In vitro techniques such as organ and monolayer cell cultures will be used to establish the direct influence progesterone and other steroids exert on the synthesis and/or secretion of these proteins. Once the proteins have been characterized and identified as being progesterone-dependent in normal tissues washes of cancerous endometria will be examined in similar fashion.