S100A9 and type 2 diabetes mellitus: Recent human studies have suggested that S100A8/A9 levels were elevated in type 2 diabetic patients (Peterson, 2002; Ortega et al., 2012) and indeed, the S100A8/S100A9 complex could be an useful biomarker for the prediction of 1-year mortality in elderly patients with severe heart failure (Ma et al., 2012).