IRS1 and Insulin resistance: Studies have found increased expression of genes related to lipid metabolism (e.g., low density lipoprotein receptor, fatty acid-binding proteins, and sterol regulatory element-binding protein 1), inflammatory cytokines [e.g., tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), and interferon gamma], and insulin resistance [e.g., glucose transporter 1, insulin receptor substrate 1 (IRS1) and Vascular endothelial growth factor (VEGF)] in patients with ORG.