LRG1 (leucine-rich alpha -2-glycoprotein 1) is an approximately 50 kDa secreted glycoprotein present in the plasma and other body fluids (1‑4). The human LRG1 cDNA encodes 347 amino acids (aa) that include a 35 aa signal sequence, eight leucine‑rich repeats (LRR), and an LRRCT (LRR C‑terminal) domain (1). Mature human LRG1 shares 66%, 63%, 75% and 72% aa sequence identity with mouse, rat, canine and porcine LRG1, respectively. LRG1 is up‑regulated during differentiation of neutrophils and present with myeloperoxidase in primary neutrophilic granules (1, 2). It can be produced by hepatocytes as an acute phase protein (5). LRG1 can interact directly with Cytochrome c, and is thought to act as a survival factor for lymphocytes in the presence of extracellular Cytochrome c (3, 6). Serum or plasma LRG1 is reported to be elevated in toxic shock syndrome, cardiac damage (produced by cardiomyocytes and correlating with BNP), autoimmune syndromes such as rheumatoid arthritis and Crohn’s disease, and some cancers such as those in the ovary and biliary tract (4, 7‑10). It is elevated in coronary sinus fluid during ventricular dysfunction and heart failure, and in peritoneal fluid of patients with uterine lyomyomas (8, 11).