It is recognised that calcineurin inhibitor (CNI) nephrotoxicity is a major factor in late renal allograft failure and dysfunction. In fact, withdrawal of CNI from patients with deteriorating graft function may improve graft function. However, there is abundant evidence that histological renal allograft damage may progress even in the absence of changes in renal function - i.e. declining renal function is a late marker of renal damage, and therefore institution of therapies (including CNI minimisation) to slow this process may be "too little, too late".