After the disappointing performance of Interleukin-2 in suppressing cancer cell growth, scientists have pinned their hopes on its successor -the Interleukin-12 (IL-12). Interleukins are a group of proteins produced by special blood cells that improve immune-system efficiency.

Recently, Judah Folkman and his colleagues at Harvard University reported that it eliminated existing tumors in the animals and helped them keep away new tumors as well (Scientific American, Vol 273, No 1).