CTLA4 and melanoma: On the other hand, according to other study., circulating B lymphocyte subsets, besides other cells like T cells, macrophages, dendritic cells, and mast cells, can produce inflammatory cytokines, such as IL-6 and TNF-α, which induce the checkpoint blockade failure, thus contributing to tumor growth and being associated with the lack of response and poor outcome of melanoma patients treated with anti-CTLA-4.