CTSS and neoplasm: Besides the pro-angiogenic and immunosuppressive effects, TAMs can also facilitate tumor cell invasion and metastasis via secreting various proteolytic enzymes, cytokines and chemokines such as MMPs, cathepsins, EGF, and CCL18 (Wyckoff et al., 2004; Gocheva et al., 2010; Su et al., 2014).