We therefore support the statement that combined clinical, biochemical, and IHC analyses of TFs and adenohypophyseal hormones provide a sliding scale that encompasses not only the distinction between clinically silent, whispering, and functioning adenomas, but also the differentiation between true NCAs (TF−/H− NFPA) and silent PAs (TF+/H± NFPA) (63). Here, TF is linked to non-functioning pituitary adenoma.