Lazaridis, Iosif, et al. “The Genetic History of the Southern Arc: A Bridge between West Asia and Europe.” Science, vol. 377, no. 6609, 2022, https://doi.org/10.1126/science.abm4247.
This is a recently published paper ('the paper', 'this paper') with many new samples from what the authors call 'The Southern Arc'. The authors define it as 'a region centred on the large Anatolian peninsula (Turkey), including in the west (in Europe) the Balkans and the Aegean, and in the south and east, Cyprus, Mesopotamia, the Levant, Armenia, Azerbaijan, and Iran.'
The main conclusion of this paper which upends one part of the Steppe theory is that West Asia is now considered to be the homeland of the first Indo-European speakers, and the steppe to be only a secondary homeland. From the paper: