Neutrophil gelatinase-associated lipocalin (NGAL) is a 25-kDa lipocalin first identified as a protein stored in specific granules of the human neutrophil. The protein is believed to bind small lipophilic substances such as bacterial derived formylpeptides and lipopolysaccharides (LPS) and might function as a modulator of inflammation. To characterize the regulation of NGAL further, we have cloned and sequenced a 5869-bp region of the NGAL gene including 1695 bp of the 5' nontranscribed region and a 3696-bp coding region encompassing seven exons and six introns. The transcriptional start sites were identified by an RNase protection assay. The NGAL gene is highly homologous to the mouse gene 24p3. NGAL was expressed in bone marrow and in tissues that are prone to exposure to microorganisms. Potential cis-acting elements were identified in the promoter region of the NGAL gene by computer analysis and include binding sites for CTF/CBP, the hematopoietic transcription factors GATA-1 and PU.1, and the LPS-inducible factor NF-kappa B.