VIPR2 and thyroid gland carcinoma: In addition, VPAC2 receptors exhibited a particular high prevalence in endocrine and neuroendocrine tumours such as thyroid carcinomas, GH-producing adenomas and neuroendocrine tumours of the gastrointestinal tract (4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14).