Although caution should be exerted when comparing normal pituitary tissues (which contain a mixture of pituitary cell subtypes) and pituitary adenomas (though to be mono/oligoclonal in origin), it should be noted that the careful use of this type of comparison has been generally accepted13, 30 as it provides potentially valuable and informative insights, and may help to set the stage for future investigations to elucidate the putative physiological role(s) for the ghrelin system in normal pituitaries and pituitary adenomas. Here, GHRL is linked to pituitary gland adenoma.