TEK and neoplasm: The protumorigenic tumor microenvironment contains immunosuppressive effects of M2-activated tumor-associated macrophages involving the production of anti-inflammatory cytokines, myeloid-derived suppressor cells, regulatory T cells and B cells, cancer-associated fibroblasts producing aberrant extracellular matrix, TIE2-expressing monocytes, and mast cells with angiogenesis stimulatory activity.