MMP9 and cholesteatoma: Further, because the local osteolytic process in the middle ear is a characteristic pattern for cholesteatoma patients, we chose to evaluate several remodeling factors, such as matrix metalloproteinase 2 (MMP-2), matrix metalloproteinase 9 (MMP-9) and the tissue inhibitors of the metalloproteinases 2 and 4 (TIMP-2; TIMP-4).