gmp writes "The NY Times and the Wall Street Journal are reporting on a new paper, published in the science journal Cell Stem Cell, where scientists, inspired by the ability of newts and other lower organisms to regrow lost limbs, have demonstrated that adult mammalian cells can be made to regenerate by suppressing a pair of anti-cancer genes. 'Interfering with tumor suppressor genes is a dangerous game, but Dr. Pomerantz said the genes could be inhibited for just a short period by applying the right dose of drug. When the drug has dissipated, the antitumor function of the gene would be restored. Finding the right combination of genes to suppress was a critical step in the new research. One of the two tumor suppressor genes is an ancient gene, known as Rb, which is naturally inactivated in newts and fish when they start regenerating tissue. Mammals possess both the Rb gene and a backup, called the Arf gene, which will close down a cancer-prone cell if Rb fails to do so.' Is regeneration nature's default, only turned off by our evolved defenses against cancer?"