An article in the New York Times describes a worrying trend: for-profit stem cell clinics that harvest bone marrow and fat, then inject or infuse them back into patients to treat conditions as various as asthma, Parkinson's disease and aging. While stem cells are known for their powerful regenerative qualities and therapeutic flexibility, these procedures have not been tested through standard research protocols or approved by the Food and Drug Administration (FDA). Nevertheless, stem cell clinics require patients to sign extensive waivers and represent a "mushrooming business [that's] almost wholly unregulated." Prof. Leigh Turner of the University of Minnesota's Center for Bioethics calls this approach "unauthorized, for-profit human experimentation" and has asked the FDA to investigate.