Streuli et al. (1980) showed that at least 3 different IFN-alpha genes are expressed in man. Furthermore, study of genomic DNA revealed the presence of at least 8 IFN genes.

Nagata et al. (1980) found that the alpha-interferon genes are devoid of intervening sequences. Using radioactive probes from purified cDNA clones of interferons, Owerbach et al. (1981) located at least 8 leukocyte interferon genes and a fibroblast interferon gene on chromosome 9. Shows et al. (1982) found that the alpha- and beta-interferon genes are on 9p. The mapping to 9pter-q12 was accomplished by blot hybridization of cloned interferon cDNA to DNA from human-mouse cell hybrids with a translocation involving chromosome 9.