beta-Core chemical and clinical properties.

beta-Core is the most abundant hCG-related molecule in pregnancy urine. The structure of beta-core as well as aspects of its metabolic clearance suggest that beta-core is a metabolic fragment of the hCG-beta subunit. The occurrence of beta-core in the urine of patients with a broad spectrum of malignancies imparts an important role to beta-core as a tumor marker. The recent development of antisera with enhanced specificity and sensitivity for beta-core will facilitate further studies on the clinical significance of this molecule.