eLife assessment
This fundamental study reports differential expression of key genes in full-term placenta between Tibetans and Han Chinese at high elevations, which are more pronounced in the placentae of male than in female fetuses. If validated as functionally relevant, these results will help us understand how human populations adapt to high elevation by mitigating the negative effects of low oxygen on fetal growth. At this time, while the differential gene expression analyses are solid, the downstream analyses offer incomplete support for the connection to hypoxia-specific responses and adaptive genetic variation.