CCL2 and macrophage activation syndrome: Careful observation revealed that the excessive cytokines and chemokines activated by macrophages (i.e., IL-6, IL-7, TNF-α, CCL-2/MCP-1, CCL-3/MIP-1α) were similar to results previously found in hemophagocytic lymphohistocytosis (HLH) and macrophage activation syndrome (MAS).