LCN1 (lipocalin 1) encodes a small lipid-binding protein that functions primarily as a versatile molecular transporter in secretory fluids. The protein demonstrates broad ligand-binding capabilities, capable of binding various hydrophobic molecules including lipids, retinoids, and even microbial compounds due to its extremely wide ligand pocket 1. Originally identified as tear prealbumin, LCN1 serves as the principal lipid-binding protein in tear fluid but is also expressed in multiple tissues including lingual von Ebner's glands, prostate, nasal mucosa, and tracheal mucosa 1. Beyond its transport function, LCN1 exhibits unique cysteine proteinase inhibitory activity similar to cystatins, a property not found in other lipocalins 1. This suggests a protective role for epithelia by scavenging potentially harmful lipophilic substances 1. The LCN1 gene is located on chromosome 9 and contains six protein-coding exons spanning approximately 6.2 kb 23. Clinically, LCN1 has emerging significance as a biomarker for diabetic retinopathy, with sensitive detection methods being developed for monitoring disease severity and treatment response 4. Additionally, PON3::LCN1 fusion proteins have been identified in salivary acinic cell carcinoma, suggesting potential diagnostic and prognostic utility in cancer 5.