CD163 and macrophage activation syndrome: This biologic blocks MCP-1/CCL2 production during experimental radiation injury [45] reduces sCD163, IL-2RA/sCD25, and ferritin production in COVID19 patients [46, 47], inhibits IL-8 and MIP-1 alpha production in mixed lymphocyte cultures without affecting t-cell function [48], and reverses MAS in children [49].