In fact, Mx1 rs2071430 polymorphism, in the promoter region, has been related to Mx1 gene expression, spontaneous viral clearance during acute HCV infection, higher hepatic fibrosis score and hepatitis activity grade, and response to IFN therapy in HCV-monoinfected patients10,11,12,13. The gene discussed is IFNA1; the disease is hepatitis A virus infection.