MMP9 and nephritis: Besides, serum level of HOTAIR had a significantly positive correlation with IL-6 (r = 0.675, P<0.0001), MMP-9 level (r = 0.757, P<0.0001), proteinuria (r = 0.287, P = 0.035) and grades of nephritis (r = 0.296, P = 0.024) (Table 3).