Glial Cell Line-Derived Neurotrophic Factor (GDNF) is a disulfide-linked homodimeric glycoprotein that belongs to the TGF-β superfamily. It has been shown to promote the survival of various neuronal subpopulations in both the central as well as the peripheral nervous systems at different stages of their development. Human GDNF cDNA encodes a 211 amino acid residue prepropeptide that is processed to yield a dimeric protein. Mature human GDNF was predicted to contain two 134 amino acid residue subunits. Cells known to express GDNF include Sertoli cells, type 1 astrocytes, Schwann cells, neurons, pinealocytes and skeletal muscle cells. Mutations in this gene may be associated with Hirschsprung disease.