LCN2 and systemic lupus erythematosus: Apart from uNGAL, serum NGAL was also detected in several included studies [21, 22, 26, 29, 33], most of the studies [21, 26, 33] showed that serum levels of NGAL were not significantly different between LN and controls, one study pointed that serum NGAL levels were statistically different between patients with active LN and those with nonactive SLE, and another study [22] indicated that serum NGAL levels increased significantly before worsening of LN as measured by the BILAG renal score.