The potential for improved clinical outcomes has also been suggested by a small dose escalation clinical trial that tested the combination of high-dose IL-2 (720,000 IU/kg) with increasing doses of ipilimumab, a humanized monoclonal antibody that blocks CTLA-4 (range 0.1 - 3.0 mg/kg) in patients with advanced melanoma [44]. Here, CTLA4 is linked to melanoma.