Although the route of secretion for transgenic proteins is not entirely predictable in vivo, we have shown that vectors targeted to the SG can lead to secretion of therapeutic levels of many transgenic proteins, such as growth hormone [8], parathyroid hormone [9], erythropoietin [10] and glucagon-like peptide-1 (GLP-1) [2] via the CSP as a potential treatment for endocrine disorders. This evidence concerns the gene GCG and endocrine system disorder.