SPP1 and anemia: Chronic renal hypoxia as well as oxidative stress or inflammation induces renal cell growth and extracellular matrix synthesis through activating several genes such as transforming growth factor-β1, osteopontin and hypoxia inducing factor-1 or inhibiting nitric oxide synthase.[30, 31] Therefore, chronic renal hypoxia is recognized to play an important role in tubulointerstitial damage.[32–34] Recently, it is appreciated that tubulointerstitial damage could play an important role in the pathogenesis of albuminuria.[34, 35] Next, anemia induces low renal blood flow thorough cardiac disorders.