A significant positive correlation between the concentration of NGAL and urinary FN and LN before (r = 0.709 and r = 0.646, both p < 0.001, respectively; Table 3) as well as after (r = 0.594 and r = 0.479, both p < 0.001, respectively; Table 3) 6 months of treatment with metformin in T2DM patients was detected. The gene discussed is LCN2; the disease is type 2 diabetes mellitus.