Uyghurs
Contemporary scholars consider modern Uyghurs to be the descendants of a number of people, including the ancient Uyghurs of Mongolia who arrived at the Tarim Basin after the fall of the Uyghur Khaganate, Iranic Saka tribes, and other Indo-European peoples who inhabited the Tarim Basin before the arrival of the Turkic Uyghurs. DNA analyses indicate that the peoples of central Asia such as the Uyghurs are all mixed Caucasian and East Asian. Uyghur activists identify with the Tarim mummies, remains of an ancient people who inhabited the region, but research into the genetics of ancient Tarim mummies and their links with modern Uyghurs remains problematic, both to Chinese government officials concerned with ethnic separatism, and to Uyghur activists concerned that the research could affect their people's claim of being indigenous to the region.
Oghuz Turks
During the 2nd century BC, according to ancient Chinese sources, a steppe tribal confederation known as the Xiongnu and their allies, the Wusun (probably an Indo-European people) defeated the neighboring Yuezhi and drove them out of western China and into Central Asia. Various scholarly theories link the Xiongnu to Turkic peoples and/or the Huns. The first usage of the word "Oghuz" appears to have been the title of "Oğuz Kağan", given in 220 BC to the Xiongnu king Modu Shanyu (or Mau-Tun), who founded the Xiongnu Empire. According to a controversial theory with few scholarly adherents, one transliteration of Yuezhi, as "Hu-chieh", may refer to the Turkic Uyghurs. However, the Yuezhi are widely believed to have spoken an Indo-European language or languages.