Editing Genestealer Cult (section)

====Tau====
Tau, similarly, have certain complications which may prevent Genestealer infestation. Firstly, their Kroot allies can tell if a person is infected or not simply by tasting some of their blood, and secondly, Tau-tech is certainly advanced enough to scan for this threat once they know about it. Furthermore, Tau explicitly practice caste-restricted bureaucratically arranged breeding processes; Tau don't have kids until their higher ups decide they should, and they don't even get to pick their own partners. Two Tau get paired up by the decision of a committee, spend a couple of days off work having sex, then separate and go their separate ways. This means the genestealer taint is seriously difficult to spread amongst the race. The caste-based structure of Tau society also poses problems to any potential Tauified Genestealers, and that's without presuming the caste-system is now so inherent that different castes can't even physically breed with each other anymore. However, fluff states that BREEDING is controlled, and doesn't touch on recreational sex. If such is unrestricted in Tau society, then it would simply be a matter of overcoming the probably enforced contraceptive measures.

Tau Genestealers are confirmed in the novel Deathwatch: Shadowbreaker as they're being deliberately engineered by a rogue Inquisitor to use a planet contested by the Tau and Imperium as a bioweapon delivery system. The narration makes it clear that the Tau are doing it without the permission of the Ethereals and that the Inquisitor is conning the Tau commander into letting it happen. However, all the Taustealers get blown up (It is a novel about the Deathwatch, after all) so they don't get a chance to spread beyond the planet. On top of all of that, according to the new Genestealer Cults Codex, not only can Tau-Genestealer hybrids happen, but one time they were ''deliberately'' created by a team of Earth Caste researchers who wanted to see what would happen. The infection got out of control and actually ended in violence. It's even implied that they may have produced a hybrid Ethereal, which would be a disaster for the Tau given how obedience to the Ethereal caste is basically hard coded into their DNA.