Renal biomarkers are measurable indicators (proteins, metabolites, genetic markers) in blood, urine, or tissue that reflect kidney function, injury, or disease progression. Key biomarkers include NGAL, KIM-1, cystatin C, clusterin, IL-18, L-FABP, TIMP-2 × IGFBP-7 (NephroCheck), and emerging multi-marker panels. These enable earlier detection of acute kidney injury (AKI), chronic kidney...