TEK and neoplasm: For instance, TIE2-expressing monocytes (TEMs) enhance angiogenesis and tumor progression (15, 16) and macrophages in solid tumors, referred to as tumor-associated macrophages (TAMs), are a poor prognostic factor and exert multiple pro-tumorigenic effects such as the promotion of angiogenesis, extracellular matrix remodeling and immunosuppression (17–19).