In addition to uCyst-C as an AKI measure, neutrophil gelatinase-associated lipocalin (NGAL), also known as human neutrophil lipocalin or lipocalin 2, exists in three molecular forms in blood and urine: a 25 kDa monomer, a 45 kDa disulfide-linked homodimer, and a 135 kDa heterodimer. The gene discussed is LCN2; the disease is acute kidney injury.