On Sept. 30, 2020, researchers at the Karolinska Institutet in Sweden and the Max Planck Institute for Evolutionary Anthropology in Germany reported that the version of the gene cluster associated with a higher risk of severe Covid-19 is very similar to the corresponding DNA sequences of a roughly 50,000-year-old Neandertal from Croatia, and indeed comes from Neandertals.

The study also revealed considerable differences in how common this genetic risk variant is in different parts of the world.