The present invention relates to a method tor suppressing neuroendocrine disease. The therapy employs use of a non-cytotoxic protease, which is targeted to a neuroendocrine tumour cell, preferably via a somatostatin or cortistatin receptor, a QHRH receptor, a ghrelin receptor, a bombesin receptor, a urotensin reccptora melanin- concentrating hormone receptor 1； a KiSS-1 receptor or a prolactin- releasing peptide receptor. When so delivered, the protease is internalised and inhibits secretion-from said tumourcell. The present invention also relates to polypeptides and nucleic acids for use in said methods.
