LCN2 and lupus nephritis: Neutrophil gelatinase-associated lipocalin (NGAL) is involved in metabolic homeostasis, apoptosis, infection, immune response, and inflammation, and is a potential clinical biomarker for the onset and progression of inflammatory diseases, including arthritic diseases, severe acute pancreatitis, obesity-related metabolic diseases, cardiovascular diseases, AKI, lupus nephritis, intestinal inflammation, and multiple sclerosis [2, 3].