Board Thread:Warhammer 40k General Discussion/@comment-6078851-20130130174042/@comment-3258762-20130315215723

Well, considering that the Alpha Legion corrupted some of the original gene-seed with an agent of chaotic order, I would say it is not at all immune.

As for the Grey Knights, I do not know if it has been written so in the Codex, in which case I will not heed it, but I have never seen any source other than Grey Knight fanboys (Mat Ward cough) that state that the Grey Knights have the Gene-Seed of the Emperor. I can believe they have mixed Gene-Seed from many different first founders to bring forth the greatest warriors, but I cannot picture someone daring to take gene-strands from the Emperor on the throne since the Grey Knights did not come until after the Emperor was placed on the Golden Throne. The Inquisition, sure, but not the GKs.