IL6 and neoplasm: Tumor infiltrating myeloid cells produce tumorigenic, pro-inflammatory cytokines (IL-6, IL-23, TNFα and IL-1) but, oddly enough, also anti-inflammatory cytokines (IL-10, TGFβ) as well as molecules with immune suppressive functions (Arginase1, VEGF, peroxinitrite and Indoleamine 2-3 dioxygenase) (62).