I'm well aware of horizontal gene transfer, but thanks for linking it anyways for the people who don't know.
Edit: My response was lacking, apologies. AFAIK, there's never been a horizontal gene transfer from a prokaryote/eukaryote/any other kingdom to a mammal or animal. The last time may be when we got mitocondria.
There is much we don't know. There are many processes of ongoing genetic transfer.
http://en.wikipedia.org/wiki/Horizontal_gene_transfer
Next time ask for clarification.