Lipocalin-1(LCN1),also known as PREALBUMIN, TEAR or VEGP, is a protein that in humans is encoded by the LCN1 gene. Lipocalin-1 is a member of the lipocalin family of small secretory proteins, which is mapped on 9q34.3. Lipocalin-1 is the primary lipid binding protein in tears and is overproduced in response to multiple stimuli including infection and stress. It may be a marker for chromosome aneuploidy as well as an autoantigen in Sjogren's syndrome. LCN1 inhibits the cysteine-protease papain in vitro, similar to cystatins. And LCN1 plays a role in the nonimmunologic defense and in the control of inflammatory processes in oral and ocular tissues. The investigations presented the first clear evidence that LCN1 is induced in infection or inflammation and supported the idea that this lipocalin functions as a physiologic protection factor of epithelia in vivo.