INTERFERON made its cover debut on the March 31, 1980, issue of Time, with the proclamation, "The Big IF in Cancer Therapy." The accompanying article called it the first biologic agent to show potential in cancer treatment, and asked, "Will its promise be fulfilled?"
Time's question, posed when interferon was available only in minute amounts and at great cost after laborious distillation from white-cell buffy coats or fibroblast monolayers, remains unanswered. But in the six years thence, since recombinant DNA technology has made ample supplies available to basic and clinical researchers, a few more details about the elusive substance have become available.
Interferon is now known to be not one protein, but a family of at least 15 proteins that are secreted by cells infected with viruses or doublestranded RNA or exposed to antigens or mitogens. The interferons bind to receptors of neighboring uninfected cells. The proteins are parceled