The effect of TIMP1 upregulation and of MMP-11 and DUSP4 downregulation can be interpreted as a decrease in the degradation process. TIMP1 promotes apposition of ECM by inhibiting collagen and other components of ECM degradation operated by the metalloproteinase [26] . DUSP4 inactivates the superfamily of MAP kinase, which is involved with proliferation and differentiation. DUSP4 downregulation, then, stimulates proliferation [17] . MMPs potentially can degrade almost all components of the periprosthetic ECM and contribute to prosthetic loosening and osteolysis through pathologic ECM degradation and bone remodeling around prostheses [28, 35] . The stromelysins especially have broad substrate specificity, including proteoglycans, laminin, and fibronectin [35] . Stromelysin-1 determines the release and activation ECMbound latent TGF-ß1 and is involved with ECM turnover [8] . Upregulation of CALM1 promotes enhancement of calmodulin1, a protein involved in proliferative cell activation [40] . Calmodulin also is involved in the transduction mechanism of PEMFs [9] .