Gov. Rick Perry is walking a thin line on science about which he has a combination of limited knowledge, personal zeal and political power that could make him dangerous.The risk is illustrated by two speeches the governor gave last week. One was to the Houston Stem Cell Summit, touted by its organizers as bringing together "the many and varied stem cell research and commercialization activities in Texas with the leading global researchers and entrepreneurs."Participants included Baylor College of Medicine, Texas Heart Institute, Texas A&M, Rice University and the MD Anderson Cancer Center. The top sponsor was Celltex Therapeutics, the Sugar Land branch of a Korean company that processed Perry's own adult stem cells for use in his unlicensed treatment after back surgery in 2011.The governor has said his support for this research and treatment is limited to using adult stem cells, not the embryonic stem cell research banned from federal support under the administration of former President George W. Bush.Perry's support is enthusiastic, both for the potential of this biomedical field and for its place in the state's economic development efforts. He has said his own treatment was successful."Texas holds the potential of becoming the nation's center for regenerative medicine," Perry said.But as with many medical advances, there are questions of safety.In September, the Food and Drug Administration sent Celltex a "warning letter," accusing the Sugar Land facility of "significant objectionable conditions" ranging from non-sterile equipment used in preparing stem cells for human treatments to inadequate record keeping. The company has denied that those conditions exist and has disputed the FDA's authority to regulate its operations.Perry told reporters after the speech that he also disagrees with FDA regulation of treatments involving a patient's own stem cells. That's despite a recent federal court decision recognizing the agency's authority because the stem cells are processed before they are used in treatment.The governor is not on the side of the angels on this one. If Texas is to be in the lead in any industry, it must be willing to insist on safety, and that means regulatory oversight.Perry gave a speech of similar note last week to a conference sponsored by the Cancer Prevention and Research Institute of Texas. CPRIT aims to fight cancer through research and commercialization grants from $3 billion in state bonds approved by voters in 2007.Through CPRIT, the governor said, "We can foresee a day when those waiting for the drug that will shrink their tumor will be waiting no longer."But there's recent controversy here, too. A report in The Wall Street Journal last week said 33 of the 140 scientists working for the institute have resigned this month. Some of them blamed what they said was improper influence from political appointees on which grant applications get funding.CPRIT's 11-member oversight committee includes nine appointed by the governor, the lieutenant governor and the speaker of the House. The two other members are the comptroller and the attorney general or their designees.There is conflict over how much of the institute's money should be used to fund basic cancer research and how much should go to help fund the development and commercialization of cancer-fighting drugs. One of the departing scientists said commercialization must be "secondary at all times to scientific quality," the Journal said.Here again, Perry must watch his step -- and that of his appointees. His public statements have focused on fighting cancer, although in many things he's an advocate of commercial ventures.Balance, governor, balance.