Purity Control was the name for a top secret government project, under the control of the Syndicate, to create alien-human hybrids. The project initially centered around using gene therapy using alien DNA to cure terminally-ill cancer patients. These patients quickly recovered, developed super-human strength and the ability to breath underwater. These patients' blood/bloodgas is incredibly toxic to humans and is green in color. The material from the sample was also used in a large scale test on livestock and humans in a small beef farming town in Wisconsin (TXF: "Red Museum").