I know that we have embryonic stem cells (controversial) and adult stem cells that can be harvested from skin tissue (not controversial, possibly difficult/expe

I know that we have embryonic stem cells (controversial) and adult stem cells that can be harvested from skin tissue (not controversial, possibly difficult/expensive?). I'm not particularly well versed in this field, but it could possibly be more expedient than other methods of getting adult stem cells. It could also be even more difficult/expensive, and that's assuming that they're pluripotent and not spleen-specific in the first place, though.