LCN2 and acute kidney injury: Because AKI is a complex, multifactorial complication, there is currently no single molecular or digital biomarker signature that is a so-called “kidney troponin.”4 At present, the most promising molecular biomarkers for AKI diagnosis are neutrophil gelatinase-associated lipocalin, interleukin-18, kidney injury molecule-1, cell-cycle arrest biomarkers,2 and N-terminal prohormone of brain natriuretic peptide, high-sensitivity C-reactive protein, hemoglobin, and magnesium.5