Schreiber says Duesberg was a respected virologist prior to this controversy.

"The best I can tell, I think Duesberg is genuinely concerned with this question," Schreiber says. "In the early days of this proposal, the evidence was less convincing, but during the period of time when he has been challenging the established AIDS theory, an enormous amount of evidence has arisen that supports the HIV theory."

According to Schreiber, Duesberg doesn't seem willing to address the new data supporting the HIV hypothesis. "He has refused invitations to comment on these new findings," Schreiber says.

Schreiber also says he is puzzled by the fact that Kary Mullis, the 1993 Nobel laureate in chemistry, is a member of the group. Schreiber says he suspects Mullis associates himself with the group to garner media attention.

Dr. Abul K. Abbas, professor of pathology at the Medical School, says, "Peter Duesberg has been supporting this line for sometime now. His proposal is controversial. The evidence in published work is overwhelming that HIV causes AIDS."

Abbas says, however, that HIV may not be the only factor involved in causing the disease.

Members of the Group for the Scientific Reappraisal of the HIV/AIDS Hypothesis call their cause the "story of the century," but Dr. Norman L. Letvin, associate professor of medicine at the Medical School, says "there is overwhelming evidence that HIV causes AIDS."

"There are a lot more useful ways to expend energy than calling for this reappraisal," Letvin adds.

But he tries to put the group in perspective. "The group's call for reappraisal may be a reflection of frustration from our inability to vaccinate AIDS."