Lipocalin-2 (LCN2)

Lipocalin‑2 is a small secreted glycoprotein encoded by the LCN2 gene. It belongs to the lipocalin family, characterized by an eight-stranded β-barrel structure that binds small hydrophobic molecules. Lipocalin‑2 is expressed predominantly by neutrophils but also at lower levels in the kidney, prostate, liver, and epithelial tissues. Its primary function is to sequester iron by binding bacterial siderophores during infection, thereby limiting bacterial growth as part of innate immunity. It also binds mammalian siderophores to regulate intracellular iron homeostasis. As an acute-phase reactant produced mainly by hepatocytes during inflammation or tissue damage, it plays roles beyond immunity—including modulation of energy metabolism and acting as a growth factor. Clinically, Lipocalin‑2 serves as a sensitive biomarker for acute kidney injury due to its rapid elevation following renal epithelial damage; it can distinguish between inflammatory versus renal sources based on its molecular form detected in biological fluids.[1][2][4]

Other names

Neutrophil gelatinase-associated lipocalin (NGAL)Oncogene 24p3SIP24 (in mouse)24p3Superinducible protein 24 (SIP24)