HCV promotes insulin resistance via impaired insulin signaling pathways (e.g., PP2A, SOCS-3, IRS), induces both viral and metabolic steatosis, and raises risk of fibrosis, atherosclerosis, and T2DM; meta-analysis confirms significantly higher T2DM incidence in chronic HCV patients. The gene discussed is IARS1; the disease is type 2 diabetes mellitus.