You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Increased gastrin is seen in : and explain in detail?
Most sensitive & specific method for identifying Zollinger Ellison syndrome is demonstration of an increased fasting serum gastrin concentration (> 150 pg/mL)