IL10 and neoplasm: MARCO ligation to modified cell-antigens, such as apoptotic cells or tumor cells, induces activation of the MEK/ERK/p90RSK/CREB signaling cascade, promoting the release of IL-10 and upregulation of PD-L1 in a STAT3-dependent manner [37], which contributes to an immunosuppressive TME through enhancing Treg cell proliferation, blocking cytotoxic CD8+ T cell and NK cell activation [38].