The process of tumour detection involved biochemical screening tests including gastrin, glucose, insulin, chromogranin-A, pancreatic polypeptide, glucagon, vasointestinal polypeptide, prolactin and IGF-1 to assess for gastrinoma, insulinoma, enteropancreatic and anterior pituitary tumours. The gene discussed is GCG; the disease is gastrin-producing neuroendocrine tumor.