Interferons

The rules for interferon nomenclature have their origins in the early 1980s, in commentaries published in Nature and Lancet. In the mid-1990s, the USAN Council and INN Experts adopted a multitiered style for creating nonproprietary names for interferons: 

• The word interferon is the first element in the name. Interferon is defined as the class name for a family of cytokines.
• A spelled-out reference to a Greek letter (e.g., alfa, beta, gamma) indicates the primary group to or family to which the substance belongs and is the second word of the name. For example, interferon alfa proteins are involved in immunity against viral infections and produced mainly by plasmacytoid dendritic cells. Interferon beta proteins are produced by fibroblasts. 
  • Examples:
    • interferon alfa-2a
    • interferon alfa-2b
    • interferon beta-1a
    • interferon beta-1b
    • interferon gamma-1a
• An Arabic numeral and letter are appended to the Greek letter by a hyphen (with no spaces) to delineate subcategories. The numbers conform to interferon nomenclature recommendations published in 1993 and 1994, when the scheme was developed. If a lowercase letter follows a number, it was assigned by USAN and INN for further differentiation, and it may be specific to a company’s product.
• A prefix may be used to differentiate interferons based on structural differences, when the sequence is the same. 
• A syllable peg- is used as a prefix to indicate pegylation of the interferon. 
• For mixtures of naturally occurring interferons, the lowercase letter "n" precedes the number. 
  • Examples:
    • interferon alfa-n1
    • interferon alfa-n2