In order to avoid the activation of the inhibitory pathways described above different antibodies have been developed, targeting PD-1, PD-L1, PD-L2 and CTLA-4 These molecules, known as “checkpoint inhibitors”, exhibited efficacy and durable clinical response in various cancer types and have already been approved for NSCLC [63, 64], melanoma [46, 65–69], kidney [70], bladder [71, 72] and Hodgkin Lymphoma [73, 74]. The gene discussed is CTLA4; the disease is melanoma.