Recipient related factors may also act as co-factors contributing to an accelerated deterioration of the functional units in the kidney, including vascular, of renal arteries and a subsequent relative hypoxia of the kidney, frequently leading to interstitial fibrosis. Interestingly, many of the pathways involved in chronic injury and fibrosis are regulated very early in the course of the injury, when the downstream effects of these alterations are still not evident by pathology.