Notes: 2'-Fluoro-2'-deoxyuridine (2'-FdU) is a derivative of the pyrimidine nucleoside uridine (Item No. 20300).{66756} Hepatitis C polyU/UC RNA strands containing 2'-FdU, unlike unmodified polyU/UC strands, bind to retinoic acid-inducible gene I (RIG-I) but do not activate RIG-I signaling in a reporter assay using Huh7 cells. 2'-FdU also has been used as a starting material in the synthesis of respiratory syncytial virus (RSV) polymerase inhibitors.{66757}