MMP2 and keratoconus: In HCFs and KC-HCFs, protein levels of MMP-1 (p = 0.0058 / p = 0.0284) and TIMP-1 were higher (p < 0.0001 / p < 0.0001) and MMP-2 was lower (p = 0.0256/ 0.0384) in contrast to Keratocytes and KC-Keratocytes, respectively.