ADM, present mainly in endothelial and vascular smooth muscle cells, can act as both a hormone and cytokine (often termed a "hormokine) in an autocrine and paracrine manner. Its potent vasodilatory and hypotensive response is elicited through an initial increase in cyclic adenosine monophosphate levels, and a subsequent production of nitric oxide. The importance of ADM in homeostasis is illustrated by its central role in the up- and down- regulation of cytokines and other mediators, as well as its own stimulatory and inhibitory effect on cytokine production. Indeed, interleukin (IL)-1β and tumor necrosis factor-alpha (TNFα) are two of the most potent triggers for ADM production. It is also up-regulated by hypoxia, bacterial products, such as lipopolysaccharide (LPS), and shear stress. Moreover, ADM has potent antimicrobial actions through membrane channel formation and lysis, and anti-apoptotic properties, it enhances renal excretion of sodium, decreases aldosterone synthesis and increases renal blood flow and urine volume. The ubiquitous and important functional role of ADM results in its clinical use in many diverse indications. Its precursor molecule, MR-proADM, has been shown to be a powerful risk assessment marker in sepsis and lower respiratory tract infections with the ability to predict 30 day mortality regardless of the underlying diagnosis. Plasma concentrations of MR-proADM have been also shown to be elevated in myocardial infarction, and to correlate with the severity of acute and chronic heart failure. Furthermore, it has been shown that it outperforms BNP and NT-BNP in predicting mortality in ED patients with dyspnea after 30 days8-12. MR-proADM is also elevated in various types of glomerulonephritis and progressively increased in patients with chronic renal failure (CKD) and has greater predictive accuracy in determining risk of CKD progression, compared to standard GFR measurements.