"Where we're going... we don't need clinical trials!"

As always with rats you get call-backs to more or less bad SF. In Varley's Steel Beach, the universal AI keeping everyone "happy" on the Moon invents a nanobot that cleans your teeth and gives your breath a minty fresh flavor. The leader of la Resistance naturally hacks it to disable it, no Man is gonna prevent me from having filthy teeth!

Also in on of Paul McAuley's short stories, the main character reflects on the total destruction of the Earth's ecosphere, which was caused by a genetically modified perfect coffee plant which took over all of life.