Enhanced production of PGE2, IL-1β, IL-6, TGF-β as well as arginase, indoleamine 2,3-dioxygenase (IDO) and IL-10 from MDSCs implicitly mediate reciprocal differentiation of Th17 and Treg cells in a defined circumstance of tumor microenvironment (65). The gene discussed is IL6; the disease is neoplasm.