CCL7, also known as MCP-3, was initially purified from cytokine-stimulated human osteosarcoma cell line (MG-63) conditioned medium. CCL7 has high similarity with CCL2/MCP-1 (71%), CCL8/MCP-2 (58%), and CCL13/MCP-4 (59%) at the amino acid level. Chemokines play a key role in inflammation and, in the initial phase, CXC chemokines chemoattract polymorphonuclear leukocytes (PMNs). The next step in the inflammatory processes is directed in part by CC chemokines, including the monocyte chemoattractant proteins (CCL2, CCL7, CCL8, and CCL13) that chemoattract additional leukocytes subsets. It has been reported that MMPs regulate chemokine bioactivity, increasing or decreasing their chemoattractant property; MMP-8 and MMP-9 modulate CXC chemokines, and MMP-2 truncates the N-terminal of CCL7, eliminating the first four amino acids producing CCL7 (5-76 residues), which leads to a loss of activity. The truncated CCL7 binds to its receptor, but it does not induce signaling transduction. MCPs are truncated by different MMPs to create potent antagonists and induce decreases in inflammation. For example, MMP-13 cleaves CCL2 and CCL7 and generates potent receptor antagonists. Also, CCL7 and CCL2 play an important role in the pathogenesis of systemic sclerosis (SSc). It has been described that they are overexpressed in SSc and activate collagen production in dermal fibroblasts. In addition, CCL7 and CCL21 are highly expressed in gastric cancer and are associated with lymph node metastasis and poor prognosis.