mark kelly | scienceinfo.net

NASA's first twin experiment showed changes in DNA in space
Scientists will need a lot of time to understand this change.
NASA astronaut modified DNA after a year in outer space
That was the result of a study from NASA, discovered from the case of twin astronaut brothers Scott Kelly and Mark Kelly.
NASA's twin astronaut experiment
NASA astronaut Scott Kelly returned to Earth after spending 340 days in space in March 2016, according to Independent.