When Dantris III was invaded by Tyranids, regiments from the nearby world of Lostock were drafted in to combat the menace. The surface of Dantris III was heavily polluted and the infestation of Tyranid organisms made fighting outside the factory-complexes almost impossible. A few companies of the Lostock 23rd were modified by the Techpriests to fight in the hellish war zone. Incorporating many organs and drug-secreting glands that enabled them to survive unprotected, as well as boosting their combat abilities. Only a handful of Gland Warriors are believed to have survived the conflict, which saw the Tyranid swarm repulsed from Dantris III.
The process by which the companies of the Lostock 23rd became Gland Warriors are understood by only a few Techpriests, and are rarely utilized, for the Inquisition invariably take an interest in the use of such technologies. Nonetheless, a number of regiments have been subjected to the process, and can be found across the galaxy.