The level of asialoglycoprotein receptors on the surface of a human hepatoma cell line (Hep G-2) are effectively modulated when grown in the presence of various desialylated glycoproteins. The loss in the ability of these receptors to bind or to endocytose ligand cannot be accounted for by internalization or by down regulation. No changes were found in the ability of these cells to transcribe or to translate mRNA. Alternate mechanisms are under investigation.