Numerous independent studies have demonstrated altered expression of MMPs within the corneal layers and/or tear film of patients with KC, especially MMP-1, MMP-2, MMP-3, MMP-7, MMP-9, and MMP-13 as well as specific TIMP-1, TIMP-2, and TIMP-3 inhibitors [9,10]. The gene discussed is TIMP2; the disease is keratoconus.