GREM1 and fibrosis: and found there is a strong correlation between urinary Gremlin (ug/gCr) and serum creatinine (mg/dL) (p < 0.001, r = 0.60) (Fig. 3A), tubulointerstitial fibrosis evaluated by Masson staining (% staining area) (p < 0.05, r = 0.50) (Fig. 3B), number of crescents (%) (p < 0.001, r = 0.53) (Fig. 3C) and presence of macrophages CD68 positive cells (area mm2/Dens) (p < 0.005, r = 0.71) (Fig. 3D).