Flavivirus structural proteins are designated E, C, and M, replacing the former nomenclature of V3 (envelope), V2 (core), and VI (membrane-like) proteins, respectively. The nonstructural proteins, formerly NVl through NV5, are designated by their apparent size in kilodaltons, prefixed by P (or GP if a glycoprotein), if they are stable unrelated end-products; the lower case p or gp is used for variants or uncharacterized products. A relationship to any structural protein is indicated by adding E, C, or M parenthetically to the designation of the appropriate nonstructural protein.