CD200 and neoplasm: In addition to their role in autoimmunity, they allow malignant cells to survive through their increased expansion and production of IL-10 and IL-35 inhibitory cytokines, which are suppressed by anti-tumor immune responses [31].The recent recognition of natural regulatory PCs, characterized by the increased expression of inhibitory receptors LAG-3, CD200, PD-L1, and PD-L2, revealed that they are significant source of B cell-derived IL-10, allowing for the suppression of anti-tumor immune responses and tumor cell spread [32].