POSTN and open-angle glaucoma: Our finding that periostin (POSTN) was upregulated at the mRNA level in POAG LC cells and at the protein level in optic nerve head tissue was interesting in that this gene is regulated by hypoxia responsive growth factors (e.g., FGF-1) and is thought to be one of the main genes involved in ECM tissue remodeling following mechanical stress in rat pulmonary arterial smooth muscle cells and human cardiac myocytes [36-38].