Before merging with Chiron Corporation in 1991 (now a part of Novartis), it developed several significant pharmaceutical drugs as well as a revolutionary DNA amplification technique.

Its early efforts involved automated methods to select for industrial microorganisms that could produce greater amounts of chemical feedstocks, antibiotics, or vaccine components.

By the late 1970s, however, three new revolutionary techniques had been developed: recombinant DNA, monoclonal antibodies, and gene expression, the foundations of the biotechnology industry.

Unfortunately, the resultant protein did not live up to its expectations as a broad-spectrum anti-cancer drug, and only much later was it approved for use to treat symptoms of multiple sclerosis.

The delay in FDA approval for IL-2 created a major funding crisis at Cetus, which had been spending a considerable fraction of its investments to produce and test the drug.