LCN2 and neoplasm: Neutrophil gelatinase-associated lipocalin (NGAL), also known as lipocalin 2, is a secreted protein possessing 178 amino acids in the form of monomers, homodimers and heterodimers [1], It is widely expressed in neutrophils, kidney, prostate, respiratory and digestive tract epithelial cells [4] and plays a vital role in natural immunity [5], anti-oxidation [6], tumorigenesis and tumour metastasis [7, 8].