Based on samples of more and less aggressive cholesteatomas (given clinical signs and the complications brought about by the disease), except for congenital cholesteatomas and patients with acquired cholesteatomas in less than 14 years (average time length taken by the cholesteatoma in order to bring about complications), we tried to show whether or not there is a correlation between the expression of type 2 metalloproteinase (MMP2) and the cholesteatoma's aggressiveness. The gene discussed is MMP2; the disease is cholesteatoma.