The US Food and Drug Administration (FDA) seems to have heeded the call of Nature Medicine’s May editorial.

Last week, the agency sought an injunction against the Colorado-based stem cell clinic Regenerative Sciences, alleging that the company is not following good manufacturing practice and that the clinic’s cultured cell product lacks safety and efficacy testing. The move comes two years after the FDA first sent a letter to the clinic’s medical director Christopher Centeno asserting that the company was operating without adequate approval for its therapies, which, the regulator asserted, counted as biological drugs.

“[W]hen companies like Regenerative Sciences fail to comply with FDA laws and regulations, they put the public’s health at risk,” Karen Midthun, acting director of the FDA’s Center for Biologics Evaluation and Research, said in a statement.

As we reported in May, Centeno maintains that by reinjecting a patient’s own cells he is practicing medicine — not producing biological drugs. As such, the FDA’s petition “is a valid position, but it is not the only position,” Centeno told Nature, adding that he continues to follow the guidelines of the International Cellular Medicine Society, an Oregon-based association that now boasts 1,100 physicians and patient, according to Nature (up from 224 physicians and researchers when we reported a few months ago).

With adult stem cell therapies still carrying an air of the Wild West, the emerging legal battle between Centeno and the FDA should help resolve the status of autologous cell-based medicinal products in the US once and for all.