It was the Ancients who modified the Ilempri to be resistant to certain Goa'uld technologies such as Zat's, and made them resistant to infestation. (SG1: "Siren Song") Aris Boch is hopeful that an antidote to the drug will be discovered, and gave Major Samantha Carter a sample for her to study in the hopes that one day his people may be freed from their subservience. (SG1: "Deadman Switch")