Goats: drug factories of the future? Credit: GTC

The US Food and Drug Administration (FDA) has adopted guidelines for regulating genetically engineered animals.

Released on 15 January, the rules have been more than a decade in the making. They follow a set of draft guidelines, released in September 2008, which drew fire for effectively treating genetically engineered animals as drugs (see _Nature_ 456, 2; 2008).

In response to other concerns about the transparency of the approval process, the new guidelines note that the agency intends to hold public advisory committee meetings before approving any genetically engineered animals.

Earlier this month, an FDA advisory committee deemed an anti-clotting drug called ATryn, produced in the milk of genetically engineered goats, to be safe — an important step towards the eventual approval of the drug for sale in US markets.