Kidney transplantation is the treatment of choice for most patients with end-stage renal disease (ESRD). Standard protocols in use typically involve three drug groups each directed to a site in the T-cell activation or proliferation cascade which are central to the rejection process: calcineurin inhibitors (e.g. cyclosporin, tacrolimus), anti-proliferative agents (e.g. azathioprine, mycophenolate mofetil) and steroids (prednisolone). It remains unclear whether new regimens are more specific or simply more potent immunosuppressants.