Genetic studies of modern and ancient Yersinia pestis DNA suggest that the origin of the Justinian plague was in Central Asia. The most basal or root level existing strains of the Yersinia pestis as a whole species are found in Qinghai, China.[12] After samples of DNA from Yersinia pestis were isolated from skeletons of Justinian plague victims in Germany,[13] it was found that modern strains currently found in the Tian Shan mountain range system are most basal known in comparison with the Justinian plague strain.[3] Additionally, a skeleton found in Tian Shan dating to around 180 AD and identified as an "early Hun" was found to contain DNA from Yersinia pestis closely related to the Tian Shan strain basal ancestor of the Justinian plague strain German samples.[4] This suggests that the expansion of nomadic peoples who moved across the Eurasian steppe, such as the Xiongnu and the later Huns, had a role in spreading plague to West Eurasia from an origin in Central Asia.[11]