When it binds to CD80 or CD86 the immune system is downregulated.39 Currently, antibodies targeting CTLA4 are widely used in many forms of tumors.40 Tremelimumab, a humanized monoclonal antibody against CTLA4, was tested in metastatic melanoma as the second‐line setting. The gene discussed is CTLA4; the disease is metastatic melanoma.