Fun thing about Chagas, the disease Assassin bugs transmit to gain their bodycount. Trypanosoma cruzi (the protozoa that cause the disease) has developed a nasty little trick where it’ll offload snippets of its DNA into the host organism. This will usually cause a auto-immune disease, both weakening the host and diverting some of the efforts of the immune system.

The interesting thing about this is one of the cells it can offload the DNA into are sex cells which means it becomes a heritable trait and becomes a part of the host genome. So there are naturally GMO humans out there with chunks of protozoa DNA in them… usually to their sorrow since the DNA is geared for causing auto-immune disorders.

Edit: Fixed typo.