CTLA4 and metastatic melanoma: More recently, monoclonal antibodies that block signaling of CTLA4 (ipilumimab, Yervoy) and PD1 (nivolumab) have induced durable clinical remissions in human patients with widely disseminated metastatic melanoma; when the two antibodies were combined, response rates were over 40% and in many instances, were durable [47,48].