Put in the language of healthcare economics, in order to be clinically useful, biomarkers must balance the competing vertices of the “iron triangle of health care”: cost, quality, and access [13]. That is, firstly, biomarkers should be affordable enough to be used effectively in the population and disease in question. Secondly, biomarkers should have adequate sensitivity and specificity to facilitate prudent clinical judgments in the population and disease in question. And thirdly, biomarkers should have broad applicability across individuals and populations whenever possible, and be from an easily obtainable tissue.
