Psychologists found a "striking" difference in intelligence after examining twins raised apart in South Korea and the United States

"Genes have a more pervasive effect on development than we ever would have supposed — still, environmental effects are important. These twins showed cultural difference in some respects," Segal told PsyPost…

https://www.psypost.org/2022/05/psychologists-found-a-striking-difference-in-intelligence-after-examining-twins-raised-apart-in-south-korea-and-the-united-states-63091

CNN: Astronaut's DNA no longer matches that of his identical twin, NASA finds

Preliminary findings from NASA indicate that 7% of Scott Kelly's genes did not return to normal once he was back on Earth. ....
https://www.cnn.com/2018/03/14/health/scott-kelly-dna-nasa-twins-study/index.html

The truth about astronaut Scott Kelly’s viral ‘space genes’ - The Washington Post

March 2016, NASA astronaut Scott Kelly returned from an unprecedented 340-day mission on the International Space Station. A year later, his doctors released preliminary results of an extensive study comparing his health to that of his earthbound identical twin, Mark. And in January, NASA announced that attendees at a recent scientific workshop agreed on the initial medical conclusion — that space travel takes a significant toll and can result in changes at the molecular level.....

https://www.washingtonpost.com/news/speaking-of-science/wp/2018/03/16/the-truth-about-astronaut-scott-kellys-viral-space-genes/