Albeit, recent studies have shown that matrix metalloproteinases MMP1 and 9, AZGP1, SFRP1, IGKC and cell adhesion molecules ICAM-1 and VCAM-1 to be specifically regulated in keratoconus [36, 71], indicating their probable exclusive role in keratoconus. Here, SFRP1 is linked to keratoconus.