M2 macrophages express a hemoglobin-haptoglobin scavenger receptor cystein-rich (CD163), the macrophage-scavenger receptor-1 (CD204), the C-type lectin mannose receptor (CD206), the macrophage receptor with collagenous structure (MARCO), arginase 1 (ARG1), and IL-10 [30], and display tissue repair and tumor-promoting features [31]. This evidence concerns the gene ARG1 and neoplasm.