TIMP2 and keratoconus: Tissue inhibitor of metalloproteinase 2 (TIMP-2) also had an average expression level of 22,041.1±5,614.6 in the normal group, 39,824.9±13,027.4 in the KCGP group, and 28,488.2±7,128.8 in the KC group (p=0.10).