TNF and keratoconus: Also, eye rubbing can elevate the level of inflammatory molecules in tears including metalloproteinase (MMPs)13, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6), and the results in stromal remodeling and keratocyte apoptosis are the main forms of organizations for cell death in keratoconus cornea [24].