Mouse CCL7 was initially identified by differential screening of a cDNA library of serum stimulated NIH 3T3 cells. CCL7 has similarity with CCL2/MCP-1 (53%) and CCL8/MCP-2 (48%) at the amino acid level. Chemokines play a key role in inflammation and in the initial phase, CXC chemokines chemoattract polymorpho-nuclear leuckocytes (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 chemoattracts additional leucocytes 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), leading 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 decrease in inflammation. For example, MMP-13 cleaves CCL2 and CCL7 and generates potent receptor antagonists. In an experimental model of myocarditis induced in MMP-2 knockout mice, an increase of CCL7 and high inflammatory response, with pronounced myocardial damage mediated by inflammatory cells, resulted from reduced degradation of CCL7 due to the absence of MMP-2.