When the U.S. Food and Drug Administration approved implanting microchips in humans, the manufacturer said it would save lives, letting doctors scan the tiny transponders to access patients' medical records almost instantly. The FDA found reasonable assurance" the device was safe, and a sub-agency even called it one of 2005's top "innovative technologies." But neither the company nor the regulators publicly mentioned this: A series of veterinary and toxicology studies, dating to the mid-1990s, stated that chip implants had "induced" malignant tumors in some lab mice and rats. "The transponders were the cause of the tumors," said Keith Johnson, a retired toxicologic pathologist, explaining ... the findings of a 1996 study he led at the Dow Chemical Co. Leading cancer specialists reviewed the research for The Associated Press and ... said the findings troubled them. Some said they would not allow family members to receive implants, and all urged further research before the glass-encased transponders are widely implanted in people. To date, about 2,000 of the so-called radio frequency identification, or RFID, devices have been implanted in humans worldwide. Did the agency know of the tumor findings before approving the chip implants? The FDA declined repeated AP requests to specify what studies it reviewed. The FDA is overseen by the Department of Health and Human Services, which, at the time of VeriChip's approval, was headed by Tommy Thompson. Two weeks after the device's approval took effect on Jan. 10, 2005, Thompson left his Cabinet post, and within five months was a board member of VeriChip Corp. and Applied Digital Solutions. He was compensated in cash and stock options.