The study showed increased levels of gelatinases and collagenases (1.9 times higher), as well as elevated MMPs, cytokines (MMP-1, MMP-3, MMP-7, MMP-13, and IL-6), and TNF-alpha and TNF-beta in the keratoconus group compared with the normal group [37]. This evidence concerns the gene MMP1 and keratoconus.