 Knockout mice have shown that neurturin does not appear essential for survival.However, evidence shows retarded growth of enteric, sensory and parasympathetic neurons in mice upon the removal of neurturin receptors.Neurturin signaling is mediated by the activation of a multi-component receptor system including the Ret tyrosine kinase (RET), a cell-surface bound GDNF family receptor-α (GFRα) protein, and a glycosyl phosphatidylinositol (GPI)-linked protein.