In OCP patients, levels of tear matrix metalloproteinases (MMPs) and myeloperoxidase (MPO) are proved significantly elevated, and tissue inhibitor of metalloproteinase-1 (TIMP-1) decreased [18]; the novel technique of LC–MS/MS has been applied to detect cortisol to cortisone ratio in human ocular bio-fluids [19], and ocular surface impression cytology was used to determine the role of neutrophils as a biomarker of disease activity and progression [20]. The gene discussed is MPO; the disease is ocular cicatricial pemphigoid.