I read somewhere about the mummies in Xinjian. Someone had made genetic tests on a few of them and concluded that compared to modern people, they were most similar to Swedes, Finns, and Sicilians. Also, their clothes were similar to Celtic style, IIRC. It was proposed these people came from central Europe after learning to ride (a few thousand years BC, I guess), so they could cross the vast plains between Europe and Xinjian. If this was really the case, it would be interesting to know why they made such a long journey.
This story also told about the political difficulties in investigating these mummies. It said as both the Chinese government and the Uighur people (natives of Xinjian) claim that this area has been their land for thousands of years, none of them were interested to let the archaeologists take DNA samples that may prove that it was actually Europeans who lived there first. So apparently they had to smuggle out the few samples they could get.
I'm sure the Evil Swedish-Finnish-Sicilian coalition will now claim Xinjian as our traditional territory
I'm sorry but I don't have the link to this story. It was a long time ago and I forgot to bookmark it...