Neutrophil gelatinase-associated lipocalin (NGAL) is a promising new biomarker of AKI.  While the cardiologists have troponins, and now highly sensitive troponins, nephrologists have been stuck using creatinine as a marker for AKI.  Creatinine has many flaws: at least 50% of kidney function must be lost before it even rises; it is highly dependent on age, [...]