So, you need to be able to classify these different endocrine path, pathologies, And the way the endocrine pathologies are classified is that if we had a problem with our target, our target hormone, that is with the adrenal cortex, then, let's say we have low cortisol and that's the only thing that's a problem within that negative feedback loop that we just discussed, then, we should see actually, a high ACTH and a high CRH, because the negative feedback loop to the pituitary and to the hypothalamus is, is missing. 